void RenderThreadImpl::OnSetWebKitSharedTimersSuspended(bool suspend) {
  if (suspend_webkit_shared_timer_) {
    EnsureWebKitInitialized();
    if (suspend) {
      webkit_platform_support_->SuspendSharedTimer();
    } else {
      webkit_platform_support_->ResumeSharedTimer();
    }
    webkit_shared_timer_suspended_ = suspend;
  }
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.