signal.hh

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 * notice, this list of conditions and the following disclaimer;
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 * neither the name of the copyright holders nor the names of its
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#ifndef __SIM_SIGNAL_HH__
#define __SIM_SIGNAL_HH__
 
#include <functional>
 
#include "base/logging.hh"
#include "sim/port.hh"
 
namespace gem5
{
 
template <typename State>
class SignalSourcePort;
 
template <typename State>
class SignalSinkPort : public Port
{
  public:
    using OnChangeFunc = std::function<void(const State &new_val)>;
 
  private:
    friend SignalSourcePort<State>;
 
    SignalSourcePort<State> *_source = nullptr;
 
    State _state = {};
    OnChangeFunc _onChange;
 
  protected:
    void
    set(const State &new_state)
    {
        if (new_state == _state)
            return;
 
        _state = new_state;
        if (_onChange)
            _onChange(_state);
    }
 
  public:
    SignalSinkPort(const std::string &_name, PortID _id=InvalidPortID) :
        Port(_name, _id)
    {}
 
    const State &state() const { return _state; }
    void onChange(OnChangeFunc func) { _onChange = std::move(func); }
 
    void
    bind(Port &peer) override
    {
        _source = dynamic_cast<SignalSourcePort<State> *>(&peer);
        fatal_if(!_source, "Attempt to bind signal pin %s to "
                "incompatible pin %s", name(), peer.name());
        Port::bind(peer);
    }
    void
    unbind() override
    {
        _source = nullptr;
        Port::unbind();
    }
};
 
template <typename State>
class SignalSourcePort : public Port
{
  private:
    SignalSinkPort<State> *sink = nullptr;
    State _state = {};
 
  public:
    SignalSourcePort(const std::string &_name, PortID _id=InvalidPortID) :
        Port(_name, _id)
    {}
 
    void
    set(const State &new_state)
    {
        _state = new_state;
        sink->set(new_state);
    }
 
    const State &state() const { return _state; }
 
    void
    bind(Port &peer) override
    {
        sink = dynamic_cast<SignalSinkPort<State> *>(&peer);
        fatal_if(!sink, "Attempt to bind signal pin %s to "
                "incompatible pin %s", name(), peer.name());
        Port::bind(peer);
    }
    void
    unbind() override
    {
        sink = nullptr;
        Port::unbind();
    }
};
 
} // namespace gem5
 
#endif //__SIM_SIGNAL_HH__