Method Heartbeat

Modules/PythonSegmentation/src/mitknnInteractiveTool.cpp:1280–1326

}

void mitk::nnInteractiveTool::Heartbeat()
{
  if (!m_Impl->Remote || !this->IsSessionRunning())
    return;

  auto pythonContext = m_Impl->GetPythonContext();
  bool expired = false;

  try
  {
    // Mirror the library's own _heartbeat_loop tolerance: only a definitive
    // SessionExpiredError means the lease is gone. Everything else is non-fatal,
    // matching the library, which keeps the session alive and surfaces a real
    // expiry on the user's next action: a transient httpx error, a
    // ServerAtCapacityError (a 503 on a beat), and a malformed response
    // (json.JSONDecodeError) all just let the next beat retry. We classify inside
    // Python and read back a flag, so a transient blip never reaches the broad
    // remote guard (WrapInRemoteGuard) that would tear the session down.
    // SessionExpiredError was imported by ConstructRemoteSession() and persists in
    // the shared dictionary for the session's lifetime.
    pythonContext->Execute(
      "try:\n"
      "    session.heartbeat()\n"
      "    nni_hb_expired = False\n"
      "except SessionExpiredError:\n"
      "    nni_hb_expired = True\n"
      "except Exception:\n"
      "    nni_hb_expired = False\n");

    expired = pythonContext->GetVariableAsBool("nni_hb_expired").value_or(false);
    pythonContext->Execute("del nni_hb_expired\n");
  }
  catch (const Exception& e)
  {
    // Heartbeat() runs from a Qt timer slot, so never let an exception escape.
    MITK_WARN << "nnInteractive: heartbeat failed unexpectedly (ignored): " << e.GetDescription();
    return;
  }

  if (expired)
  {
    // The lease is gone server-side. Signal the GUI, which tears the dead
    // session down on the next event-loop tick (same deferred path used for a
    // connection loss detected mid-interaction).
    this->SessionExpiredEvent.Send();
  }
}

mitk::nnInteractiveTool::SupportedInteractions mitk::nnInteractiveTool::GetSupportedInteractions() const
{