code: def _trackInstanceAndCheckForConcurrencyViolation(self):
      
      global g_max_concurrency, g_max_concurrency_raise_exception
  
      assert g_max_concurrency is not None
      assert self not in self._clsOutstandingInstances, repr(self)
  
      # Populate diagnostic info
      self._creationTracebackString = traceback.format_stack()
  
      # Check for concurrency violation
      if self._clsNumOutstanding >= g_max_concurrency:
        # NOTE: It's possible for _clsNumOutstanding to be greater than
        #  len(_clsOutstandingInstances) if concurrency check was enabled after
        #  unrelease allocations.
        errorMsg = ("With numOutstanding=%r, exceeded concurrency limit=%r "
                    "when requesting %r. OTHER TRACKED UNRELEASED "
                    "INSTANCES (%s): %r") % (
          self._clsNumOutstanding, g_max_concurrency, self,
          len(self._clsOutstandingInstances), self._clsOutstandingInstances,)
  
        self._logger.error(errorMsg)
  
        if g_max_concurrency_raise_exception:
          raise ConcurrencyExceededError(errorMsg)
  
  
      # Add self to tracked instance set
      self._clsOutstandingInstances.add(self)
      self._addedToInstanceSet = True
  
      return
docs: Check for concurrency violation and add self to
      _clsOutstandingInstances.
  
      ASSUMPTION: Called from constructor BEFORE _clsNumOutstanding is
      incremented