source: trunk/FACT++/src/StateMachineDim.cc@ 10312

// **************************************************************************
/** @class StateMachineDim

@brief Class for a state machine implementation within a DIM network

This class implements a StateMachine within a Dim network. It redirects
all output posted via MessageImp to a service called "NAME/MESSAGE"
while name is the name of the machine given in the constructor. In
addition two services are offered: NAME/STATE and NAME/VERSION.
NAME/STATE propagates any state change to the netork.

When constructing the Dim network is started and while dstruction it is
stopped.

@todo
    Proper support for versioning

*/
// **************************************************************************
#include "StateMachineDim.h"

#include "tools.h"

#include "Time.h"
#include "EventDim.h"

using namespace std;

const int StateMachineDim::fVersion = 42;

// --------------------------------------------------------------------------
//
//! The constrcutor first initialized DimStart with the given machine name.
//! DimStart is just a wrapper which constructor calls DimServer::start()
//! to ensure that initializing the Dim sub-system, is the first what is
//! done.
//!
//! The second objet instantiated is the MessageDim class which offers
//! the MESSAGE service used to broadcast logging messages to other
//! Dim clients.
//!
//! After this the services STATE and VERSION are setup. STATE will
//! be used to broadcast the state of the machine. Version broadcasts
//! the global version number of the StateMachineDim implementation
//!
//! After redirecting the handler which handels dim's EXIT command
//! to ourself (it will then call StateMachineDim::exitHandler) and
//! adding human readable state names for the default states
//! implemented by StateMachingImp the state is set to kSM_Initializing.
//! Warning: The EXIT handler is global!
//!
//! @param name
//!    The name with which the dim-services should be prefixed, e.g.
//!    "DRIVE" will lead to "DRIVE/SERVICE". It is also propagated
//!    to DimServer::start()
//!
//! @param out
//!    A refrence to an ostream which allows to redirect the log-output
//!    to something else than cout. The default is cout. The reference
//!    is propagated to fLog
//!
//! @todo
//!    - Shell the VERSION be set from the derived class?
//
StateMachineDim::StateMachineDim(ostream &out, const std::string &name)
: StateMachine(out, name), DimStart(name, *this), fLog(name, out),
fSrvState(Form("%s/STATE", name.c_str()).c_str(), const_cast<char*>("")),
fSrvVersion(Form("%s/VERSION", name.c_str()).c_str(), const_cast<int&>(fVersion))
{
    // WARNING: This exit handler is GLOBAL!
    DimServer::addExitHandler(this);
}

// --------------------------------------------------------------------------
//
//! Overwrite StateMachineImp::AddTransition to create a EventDim
//! instead of an Event object. The event name propagated to the EventDim
//! is fName+"/"+name.
//!
//! For parameter description see StateMachineImp.
//!
EventImp *StateMachineDim::CreateEvent(int targetstate, const char *name, const char *fmt)
{
    return new EventDim(targetstate, GetName()+"/"+name, fmt, this);
}

// --------------------------------------------------------------------------
//
//! Overwrite StateMachineImp::SetCurrentState. In addition to
//! calling StateMachineImo::SetCurrentState the new state is also
//! distributed via the DimService STATE.
//!
//! For parameter description see StateMachineImp.
//!
string StateMachineDim::SetCurrentState(int state, const char *txt, const std::string &cmd)
{
    const string msg = StateMachineImp::SetCurrentState(state, txt, cmd);
    if (msg.empty())
        return "";

    fSrvState.setQuality(state);
    fSrvState.setData(const_cast<char*>(msg.c_str()));
    fSrvState.updateService();

    return msg;
}

// --------------------------------------------------------------------------
//
//! Overwritten DimCommand::commandHandler()
//!
//! If fCurrentState is smaller than 0 or we are in kSM_FatalError state,
//! all incoming commands are ignored.
//!
//! The commandHandler will go through the list of available commands
//! (fListOfEventss). If the received command was recognized, it is added
//! via PushCommand into the fifo.
//!
//! @todo
//!    - Fix the exit when cmd is not of type EventImp
//!    - Fix docu
//!    - Do we need a possibility to suppress a call to "HandleEvent"
//!      or is a state<0 enough?
//
void StateMachineDim::commandHandler()
{
    DimCommand *cmd = getCommand();
    if (!cmd)
        return;

    const EventImp *evt = dynamic_cast<EventImp*>(cmd);

    // FIXME: In the case of HandleEvent there is no need to copy the data
    // FIMXE: Currentyl the time is not copied
    // FIXME: Handle Event is not thread safe (Dim + Console)
    if (HasEvent(evt))
        PostEvent(*evt);
}

// --------------------------------------------------------------------------
//
//! Overwrites MessageImp::Update. This redirects output issued via
//! MessageImp to MessageDim object.
//
int StateMachineDim::Write(const Time &time, const char *txt, int qos)
{
    return fLog.Write(time, txt, qos);
}

// --------------------------------------------------------------------------
//
//! exitHandler of the DimServer. The EXIT command is implemented by each
//! DimServer automatically. exitHandler calls Stop(code) and exit(-1)
//! in case the received exit-value is a special number (42). abort()
//! is called if 0x42 is received.
//!
//! @param code
//!    value which is passed to Stop(code)
//
void StateMachineDim::exitHandler(int code)
{
    Out() << " -- " << Time().GetAsStr() << ": EXIT(" << code << ") command received." << endl;
    if (code<0) // negative values reserved for internal use
    {
        Out() << " -- " << Time().GetAsStr() << ": ignored." << endl;
        return;
    }

    Stop(code);
    if (code==42)
        exit(-1);
    if (code==0x42)
        abort();
}