Question

我对QStateMachine有一个奇怪的问题，我一个星期都无法解决。

简要说明：

我在我的应用程序中使用QStateMachine来控制向通过COM端口连接的生物医学设备发送命令。整个状态机复杂，有数百个状态和频繁的变电站。

根据用户的偏好，从设备的通信协议生成机器。例如，如果用户想要来自设备的某些“反应”，则该反应由若干子反应组成，这些子反应由基本步骤（设备的指令）组成。应用程序从这些基本步骤构建完整的反应，并在状态机上启动它。

因此，我创建了类 CompositeReactionControl （继承自QState），它允许从特定的子状态构建复合。

QSignalTransition实例用于将状态连接在一起。

问题描述：

有时，当发出先前状态的finish（）信号时，机器不会从一种状态转换到另一种状态。

备注：

我100％确定状态已连接。
我百分百肯定会发出信号。
事件通过机器及其状态在与应用程序其余部分分开的线程中运行，此特定信号被触发并在SAME线程中捕获
在所有反应中随机发生（没有特定的反应或与此问题相关的子状态）
在一次运行（反应）中引起问题的基质，在相同反应的其他运行中没有任何问题地运行
当StateMachine长时间运行时，它会在第4次反应之前出现（无论用户选择哪种反应）。

CODE

有问题的部分在以下代码中标有“HERE IS PROBLEM”注释......

将新子状态添加到CompositeReactionControl：

/**
 * @brief Add new reaction control as a child of this composite
 * @param reaction child reaction (inherited from QState)
 * @return added child reaction
 */
AbstractReactionControl* CompositeReactionControl::addChildReaction(
    AbstractReactionControl* reaction) {

  // Check whether reaction is valid
  if (reaction == NULL) {
    QString msg = tr("Cannot add NULL subreaction to reaction '%1'.");
    Logger::getInstance()->addError(msg.arg(getName()), this);
    return NULL;
  }

  // Adopt reaction
  reaction->setParent(this);

  // Store previous reaction control and add current to list
  AbstractReactionControl* prev = controls.size() > 0 ? controls.last() : NULL;
  controls.append(reaction);

  // Connects current state
  connect(reaction, SIGNAL(reactionEntered(core::AbstractCommunicationState*)),
          SLOT(onSubReactionEntered(core::AbstractCommunicationState*)));
  connect(reaction, SIGNAL(reactionFinished(core::AbstractCommunicationState*)),
          SLOT(onSubReactionFinished(core::AbstractCommunicationState*)));

  // If previous state does not exist (this is the first one) then set current
  // state 'c' as initial state and add transition from 'c' to final state
  // Otherwise add transition from previous state to 'c', remove transition from
  // previous state to final state and add transition from 'c' to final state
  if (prev == NULL) {
    this->setInitialState(reaction);
    this->firstState = reaction;
  } else {

    // Remove end transitions from previous state
    prev->removeTransition(endTransition1);
    prev->removeTransition(endTransition2);
    delete endTransition1;
    delete endTransition2;

    // Replaced with PassTransition
    //prev->addTransition(prev, SIGNAL(finished()), reaction);

    // HERE IS PROBLEM: I am 100% sure that finished() signal is emitted,
    // but sometimes not caught by transition
    PassTransition* t = new PassTransition(this, prev, SIGNAL(finished()));
    t->setTargetState(reaction);
    prev->addTransition(t);
  }

  // Assign new end transitions to current state
  endTransition1 = new RepeatTransition(this, reaction, SIGNAL(finished()));
  endTransition2 = new FinishTransition(this, reaction, SIGNAL(finished()));  
  endTransition1->setTargetState(firstState);
  endTransition2->setTargetState(allFinished);
  reaction->addTransition(endTransition1);
  reaction->addTransition(endTransition2);

  // Finish if halt
  reaction->addTransition(this, SIGNAL(halt()), allFinished);

  // Exit reaction
  return reaction;
}
//---------------------------------------------------------------------------

PassTransition：

/**
 * @class PassTransition
 * @brief Passes control from one substate to another
 * @author Michal Rost
 * @date 6.11.2013
 */
class PassTransition : public QSignalTransition {
public:
  PassTransition(CompositeReactionControl* owner, QObject* sender,
                 const char *signal) : QSignalTransition(sender, signal) {
    this->owner = owner;
  }
protected:
  CompositeReactionControl* owner;
  bool eventTest(QEvent *event) {

    // HERE IS PROBLEM: I know that signal is called, but event is not received

    QString msg = tr("Event Test %1, source: %2   target: %3");
    AbstractReactionControl* s = dynamic_cast<AbstractReactionControl*>(this->sourceState());
    AbstractReactionControl* t = dynamic_cast<AbstractReactionControl*>(this->targetState());
    common::Logger::getInstance()->addDebug(msg.arg(event->type()).arg(s->getName()).arg(t->getName()), this);
    return QSignalTransition::eventTest(event);
  }
  void onTransition(QEvent *event) {
    QSignalTransition::onTransition(event);
    QString msg = tr("Transition called");
    common::Logger::getInstance()->addDebug(msg, this);
  }
};

从好案例中记录

在这种情况下，一切运作良好。重要的是PassTransition :: EventTest接收类型为192的事件，该事件是从先前状态的finished（）信号创建的状态机事件。

[08:33:01:976][core::CompositeReactionControl] State 'send_fluorescence_on' finished, disconnecting...
[08:33:01:976][core::CompositeReactionControl] State 'ProfileData' removed control from 'send_fluorescence_on' substate.
[08:33:01:977][core::ReactionEmitter] Sending state entered. Timer Started.
[08:33:01:977][core::PassTransition] Event Test 0, source: send_fluorescence_on   target: send_fluorescence_off
[08:33:01:977][core::PassTransition] Event Test 0, source: measure_fluorescence   target: measure_fluorescence
[08:33:01:977][core::PassTransition] Event Test 192, source: send_fluorescence_on   target: send_fluorescence_off
[08:33:01:977][core::PassTransition] Transition called
[08:33:01:977][core::CompositeReactionControl] State 'ProfileData' gave control to 'send_fluorescence_off' substate.

从不良案例中记录

可以看出，如果出现错误RANDOMLY，则PassTransition :: EventTest方法不会收到上述事件。超过5秒后（我尝试更长的间隔），我停止状态机和打印错误。

[08:33:01:991][core::CompositeReactionControl] State 'send_fluorescence_off' finished, disconnecting...
[08:33:01:991][core::CompositeReactionControl] State 'ProfileData' removed control from 'send_fluorescence_off' substate.
[08:33:01:991][core::ReactionEmitter] Sending state entered. Timer Started.
[08:33:01:991][core::PassTransition] Event Test 0, source: send_fluorescence_off   target: led_off
[08:33:01:991][core::PassTransition] Event Test 0, source: measure_fluorescence   target: measure_fluorescence
[08:33:16:966][core::ReactionEmitter] State machine is frozen. Reaction will be stopped!

带QSignalTransition的QStateMachine丢失信号

0 个答案: