signal.hh

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#ifndef LibMultiSense_details_signal_hh
#define LibMultiSense_details_signal_hh
 
#include "MultiSense/details/utility/Thread.hh"
#include "wire/Protocol.hh"
#include "wire/AckMessage.hh"
 
#include <map>
 
namespace crl {
namespace multisense {
namespace details {
 
//
// Here we provide a thread-safe, blocking, signaling
// interface for sensor message RX.
 
class MessageWatch {
public:
 
    void signal(wire::IdType id,
                Status       status=Status_Ok) {
        utility::ScopedLock lock(m_lock);
 
        Map::iterator it = m_map.find(id);
 
        if (m_map.end() != it)
            it->second->post(status);
    };
 
    void signal(const wire::Ack& ack) {
        signal(ack.command, ack.status);
    };
 
private:
 
    friend class ScopedWatch;
 
    typedef utility::WaitVar<Status>        Signal;
    typedef std::map<wire::IdType, Signal*> Map;
 
    void insert(wire::IdType type,
                Signal      *signalP) {
        utility::ScopedLock lock(m_lock);
 
        Map::const_iterator it = m_map.find(type);
 
        //
        // Hmm.. this will prohibit multiple threads
        // simultaneously commanding the sensor with this
        // message ID.
 
        if (m_map.end() != it)
            CRL_EXCEPTION("ack signal already set for id=%d", type);
 
        m_map[type] = signalP;
    };
 
    void remove(wire::IdType type) {
        utility::ScopedLock lock(m_lock);
 
        Map::iterator it = m_map.find(type);
 
        if (m_map.end() == it)
            CRL_EXCEPTION("ack signal not found for id=%d\n", type);
 
        m_map.erase(it);
    };
 
    utility::Mutex m_lock;
    Map            m_map;
};
 
 //
 // Exception-safe [de]registration of signal handlers
 
class ScopedWatch {
public:
 
    ScopedWatch(wire::IdType  t,
                MessageWatch& m) : m_id(t), m_map(m) {
        m_map.insert(m_id, &m_signal);
    };
 
    ~ScopedWatch() {
        m_map.remove(m_id);
    };
 
    bool wait(Status&       status,
              const double& timeout) {
        return m_signal.timedWait(status, timeout);
    };
 
private:
 
    wire::IdType         m_id;
    MessageWatch&        m_map;
    MessageWatch::Signal m_signal;
};
 
} // namespace details
} // namespace multisense
} // namespace crl
 
 
#endif //  LibMultiSense_details_signal_hh