Files
pvData/src/monitor/pv/monitor.h
Michael Davidsaver c0b69e4e6f add monitor buffer statistics
to help answer the question of why no monitorEvent()s
are happening.
2017-04-15 16:05:26 -04:00

129 lines
3.5 KiB
C++

/* monitor.h */
/*
* Copyright information and license terms for this software can be
* found in the file LICENSE that is included with the distribution
*/
/**
* @author mrk
*/
#ifndef MONITOR_H
#define MONITOR_H
#include <pv/status.h>
#include <pv/destroyable.h>
#include <pv/pvData.h>
#include <pv/sharedPtr.h>
#include <pv/bitSet.h>
#include <pv/requester.h>
#include <shareLib.h>
namespace epics { namespace pvData {
class MonitorElement;
typedef std::tr1::shared_ptr<MonitorElement> MonitorElementPtr;
typedef std::vector<MonitorElementPtr> MonitorElementPtrArray;
class Monitor;
typedef std::tr1::shared_ptr<Monitor> MonitorPtr;
/**
* @brief An element for a monitorQueue.
*
* Class instance representing monitor element.
* @author mrk
*/
class epicsShareClass MonitorElement {
public:
POINTER_DEFINITIONS(MonitorElement);
MonitorElement(){}
MonitorElement(PVStructurePtr const & pvStructurePtr)
: pvStructurePtr(pvStructurePtr),
changedBitSet(BitSet::create(static_cast<uint32>(pvStructurePtr->getNumberFields()))),
overrunBitSet(BitSet::create(static_cast<uint32>(pvStructurePtr->getNumberFields())))
{}
PVStructurePtr pvStructurePtr;
BitSet::shared_pointer changedBitSet;
BitSet::shared_pointer overrunBitSet;
};
/**
* @brief Monitor changes to fields of a pvStructure.
*
* This is used by pvAccess to implement monitors.
* @author mrk
*/
class epicsShareClass Monitor : public Destroyable{
public:
POINTER_DEFINITIONS(Monitor);
virtual ~Monitor(){}
/**
* Start monitoring.
* @return completion status.
*/
virtual Status start() = 0;
/**
* Stop Monitoring.
* @return completion status.
*/
virtual Status stop() = 0;
/**
* If monitor has occurred return data.
* @return monitorElement for modified data.
* Must call get to determine if data is available.
*/
virtual MonitorElementPtr poll() = 0;
/**
* Release a MonitorElement that was returned by poll.
* A poll() must be called after the release() to check the presence of any modified data.
* @param monitorElement
*/
virtual void release(MonitorElementPtr const & monitorElement) = 0;
struct Stats {
size_t nfilled; //!< # of elements ready to be poll()d
size_t noutstanding; //!< # of elements poll()d but not released()d
size_t nempty; //!< # of elements available for new remote data
};
virtual void getStats(Stats& s) const {
s.nfilled = s.noutstanding = s.nempty = 0;
}
};
/**
* @brief Callback implemented by monitor clients.
*
* Requester for ChannelMonitor.
* @author mrk
*/
class epicsShareClass MonitorRequester : public virtual Requester {
public:
POINTER_DEFINITIONS(MonitorRequester);
virtual ~MonitorRequester(){}
/**
* The client and server have both completed the createMonitor request.
* @param status Completion status.
* @param monitor The monitor
* @param structure The structure defining the data.
*/
virtual void monitorConnect(Status const & status,
MonitorPtr const & monitor, StructureConstPtr const & structure) = 0;
/**
* A monitor event has occurred.
* The requester must call Monitor.poll to get data.
* @param monitor The monitor.
*/
virtual void monitorEvent(MonitorPtr const & monitor) = 0;
/**
* The data source is no longer available.
* @param monitor The monitor.
*/
virtual void unlisten(MonitorPtr const & monitor) = 0;
};
}}
#endif /* MONITOR_H */