StringAttr InsertToSymbolTable(Operation& module, Operation& function,
                               const StringRef func_name) {
  static tensorflow::mutex* mtx = new tensorflow::mutex();
  tensorflow::mutex_lock lock(*mtx);

  SymbolTable symbol_table(&module);
  std::string unique_name = func_name.str();
  int32_t uniquing_counter = 0;
  while (symbol_table.lookup(unique_name) != nullptr) {
    ++uniquing_counter;

  return absl::OkStatus();
}

// Tracks monotonic sequence numbers for graphs.
class ClusterSequenceNumberGenerator {
 public:
  void Reset() {
    mutex_lock lock(mu_);
    sequence_numbers_.clear();
  }

  int64 GetNext(uint64 key) {
    mutex_lock lock(mu_);
    return sequence_numbers_[key]++;
  }

  static ClusterSequenceNumberGenerator& Global() {
    static ClusterSequenceNumberGenerator* gen =

  ASSERT_EQ(TF_OK, TF_GetCode(s_)) << TF_Message(s_);

  TF_DeleteFunction(grad_func);

  const StackTracesMap* func_stack_traces;
  const StackTracesMap* grad_stack_traces;

  {
    mutex_lock l(host_graph_->mu);
    auto flib_def = host_graph_->graph.flib_def();
    func_stack_traces = flib_def.GetStackTraces(func_name_);
    grad_stack_traces = flib_def.GetStackTraces("MyGrad");
  }

// while allowing other goroutines to run.

const (
	mutex_unlocked = 0
	mutex_locked   = 1

	active_spin     = 4
	active_spin_cnt = 30
)

func mutexContended(l *mutex) bool {
	return false
}

func lock(l *mutex) {
	lockWithRank(l, getLockRank(l))
}

func lock2(l *mutex) {
	if l.key == mutex_locked {
		// wasm is single-threaded so we should never
		// observe this.
		throw("self deadlock")

//	futexwakeup(addr *uint32, cnt uint32)
//		If any procs are sleeping on addr, wake up at most cnt.

const (
	mutex_unlocked = 0
	mutex_locked   = 1
	mutex_sleeping = 2

	active_spin     = 4
	active_spin_cnt = 30
	passive_spin    = 1
)

// Possible lock states are mutex_unlocked, mutex_locked and mutex_sleeping.
// mutex_sleeping means that there is presumably at least one sleeping thread.

const (
	mutex_unlocked = 0
	mutex_locked   = 1

	note_cleared = 0
	note_woken   = 1
	note_timeout = 2

	active_spin     = 4
	active_spin_cnt = 30
	passive_spin    = 1
)

func mutexContended(l *mutex) bool {
	return false
}

func lock(l *mutex) {
	lockWithRank(l, getLockRank(l))
}

func lock2(l *mutex) {
	if l.key == mutex_locked {
		// js/wasm is single-threaded so we should never

  // contention in production code, but is acceptable in a testing
  // framework.

  // Join an existing circle.
  void join(linked_ptr_internal const* ptr)
      GTEST_LOCK_EXCLUDED_(g_linked_ptr_mutex) {
    MutexLock lock(&g_linked_ptr_mutex);

    linked_ptr_internal const* p = ptr;
    while (p->next_ != ptr) p = p->next_;
    p->next_ = this;
    next_ = ptr;
  }

  // contention in production code, but is acceptable in a testing
  // framework.

  // Join an existing circle.
  void join(linked_ptr_internal const* ptr)
      GTEST_LOCK_EXCLUDED_(g_linked_ptr_mutex) {
    MutexLock lock(&g_linked_ptr_mutex);

    linked_ptr_internal const* p = ptr;
    while (p->next_ != ptr) p = p->next_;
    p->next_ = this;
    next_ = ptr;
  }

	`(base::Mutex::)?Unlock.*`,
	`(base::Mutex::)?UnlockSlow.*`,
	`(base::Mutex::)?ReaderUnlock.*`,
	`(base::MutexLock::)?~MutexLock.*`,
	`(Mutex::)?AwaitCommon.*`,
	`(Mutex::)?Unlock.*`,
	`(Mutex::)?UnlockSlow.*`,
	`(Mutex::)?ReaderUnlock.*`,
	`(MutexLock::)?~MutexLock.*`,
	`(SpinLock::)?Unlock.*`,
	`(SpinLock::)?SlowUnlock.*`,
	`(SpinLockHolder::)?~SpinLockHolder.*`,

  GTEST_DISALLOW_COPY_AND_ASSIGN_(ThreadWithParam);
};

// MutexBase and Mutex implement mutex on pthreads-based platforms. They
// are used in conjunction with class MutexLock:
//
//   Mutex mutex;
//   ...
//   MutexLock lock(&mutex);  // Acquires the mutex and releases it at the end
//                            // of the current scope.
//
// MutexBase implements behavior for both statically and dynamically