    // @(#)root/base:$Name:  $:$Id: TQConnection.cxx,v 1.18 2004/04/15 10:13:41 rdm Exp $
    // Author: Valeriy Onuchin & Fons Rademakers   15/10/2000

    /*************************************************************************
     * Copyright (C) 1995-2000, Rene Brun and Fons Rademakers.               *
     * All rights reserved.                                                  *
     *                                                                       *
     * For the licensing terms see $ROOTSYS/LICENSE.                         *
     * For the list of contributors see $ROOTSYS/README/CREDITS.             *
     *************************************************************************/

    //////////////////////////////////////////////////////////////////////////
    //                                                                      //
    // TQConnection class is an internal class, used in the object          //
    // communication mechanism.                                             //
    //                                                                      //
    // TQConnection:                                                        //
    //    -  is a list of signal_lists containing pointers                  //
    //       to this connection                                             //
    //    -  receiver is the object to which slot-method is applied         //
    //                                                                      //
    // This implementation is provided by                                   //
    // Valeriy Onuchin (onuchin@sirius.ihep.su).                            //
    //                                                                      //
    //////////////////////////////////////////////////////////////////////////

    #include "TQConnection.h"
    #include "TRefCnt.h"
    #include "TClass.h"
    #include "Api.h"
    #include "G__ci.h"
    #include "Riostream.h"
    #include "TVirtualMutex.h"
    #include "THashTable.h"

    ClassImpQ(TQConnection)

    char *gTQSlotParams;          // used to pass string parameter

    //////////////////////////////////////////////////////////////////////////
    //                                                                      //
    //  TQSlot = slightly modified TMethodCall class                        //
    //           used in the object communication mechanism                 //
    //                                                                      //
    //////////////////////////////////////////////////////////////////////////
    class TQSlot : public TObject, public TRefCnt {

    protected:
       G__CallFunc   *fFunc;      // CINT method invocation environment
       Long_t         fOffset;    // offset added to object pointer
       TString        fName;      // full name of method
       Int_t          fExecuting; // true if one of this slot's ExecuteMethod methods is being called

    public:
       TQSlot(TClass *cl, const char *method, const char *funcname);
       TQSlot(const char *class_name, const char *funcname);
       virtual ~TQSlot();

       const char *GetName() const { return fName.Data(); }

       void ExecuteMethod(void *object);
       void ExecuteMethod(void *object, Long_t param);
       void ExecuteMethod(void *object, Double_t param);
       void ExecuteMethod(void *object, const char *params);
       void ExecuteMethod(void *object, Long_t *paramArr, Int_t nparam = -1);
       void Print(Option_t *opt= "") const;
       void ls(Option_t *opt= "") const { Print(opt); }

       Bool_t IsExecuting() const { return fExecuting > 0; }
    };

    //______________________________________________________________________________
    TQSlot::TQSlot(TClass *cl, const char *method_name,
                   const char *funcname) : TObject(), TRefCnt()
    {
       // Create the method invocation environment. Necessary input
       // information: the class, full method name with prototype
       // string of the form: method(char*,int,float).
       // To initialize class method with default arguments, method
       // string with default parameters should be of the form:
       // method(="ABC",1234,3.14) (!! parameter string should
       // consists of '=').
       // To execute the method call TQSlot::ExecuteMethod(object,...).

       fFunc      = 0;
       fOffset    = 0;
       fName      = "";
       fExecuting = 0;

       // cl==0, is the case of interpreted function.

       fName = method_name;

       char *method = new char[strlen(method_name)+1];
       if (method) strcpy(method, method_name);

       char *proto;
       char *tmp;
       char *params = 0;

       // separate method and protoype strings

       if ((proto = strchr(method,'('))) {

          // substitute first '(' symbol with '0'
          *proto++ = '0';

          // last ')' symbol with '0'
          if ((tmp = strrchr(proto,')'))) *tmp = '0';
          if ((params = strchr(proto,'='))) *params = ' ';
       }

       R__LOCKGUARD(gCINTMutex);
       fFunc = new G__CallFunc;

       // initiate class method (function) with proto
       // or with default params

       if (cl) {
          params ?
          fFunc->SetFunc(cl->GetClassInfo(), method, params, &fOffset) :
          fFunc->SetFuncProto(cl->GetClassInfo(), method, proto, &fOffset);
       } else {
          G__ClassInfo gcl;
          params ?
          fFunc->SetFunc(&gcl, (char*)funcname, params, &fOffset) :
          fFunc->SetFuncProto(&gcl, (char*)funcname, proto, &fOffset);
       }

       // cleaning
       delete [] method;
    }

    //______________________________________________________________________________
    TQSlot::TQSlot(const char *class_name, const char *funcname) :
       TObject(), TRefCnt()
    {
       // Create the method invocation environment. Necessary input
       // information: the name of class (could be interpreted class),
       // full method name with  prototype or parameter string
       // of the form: method(char*,int,float).
       // To initialize class method with default arguments, method
       // string with default parameters  should be of the form:
       // method(="ABC",1234,3.14) (!! parameter string should
       // consists of '=').
       // To execute the method call TQSlot::ExecuteMethod(object,...).

       fFunc      = 0;
       fOffset    = 0;
       fName      = funcname;
       fExecuting = 0;

       char *method = new char[strlen(funcname)+1];
       if (method) strcpy(method, funcname);

       char *proto;
       char *tmp;
       char *params = 0;

       // separate method and protoype strings

       if ((proto =  strchr(method,'('))) {
          *proto++ = '0';
          if ((tmp = strrchr(proto,')'))) *tmp  = '0';
          if ((params = strchr(proto,'='))) *params = ' ';
       }

       R__LOCKGUARD(gCINTMutex);
       fFunc = new G__CallFunc;

       G__ClassInfo gcl;

       if (!class_name)
          ;                       // function
       else
          gcl.Init(class_name);   // class

       if (params)
          fFunc->SetFunc(&gcl, method, params, &fOffset);
       else
          fFunc->SetFuncProto(&gcl, method, proto , &fOffset);

       delete [] method;
       return;
    }

    //______________________________________________________________________________
    TQSlot::~TQSlot()
    {
       // TQSlot dtor.

       // don't delete executing environment of a slot that is being executed
       if (!fExecuting)
          delete fFunc;
    }

    //______________________________________________________________________________
    inline void TQSlot::ExecuteMethod(void *object)
    {
       // ExecuteMethod the method (with preset arguments) for
       // the specified object.

       void *address = 0;
       if (object) address = (void*)((Long_t)object + fOffset);
       R__LOCKGUARD(gCINTMutex);
       fExecuting++;
       fFunc->Exec(address);
       fExecuting--;
       if (!TestBit(kNotDeleted) && !fExecuting)
          delete fFunc;
    }

    //______________________________________________________________________________
    inline void TQSlot::ExecuteMethod(void *object, Long_t param)
    {
       // ExecuteMethod the method for the specified object and
       // with single argument value.

       void *address = 0;
       R__LOCKGUARD(gCINTMutex);
       fFunc->ResetArg();
       fFunc->SetArg(param);
       if (object) address = (void*)((Long_t)object + fOffset);
       fExecuting++;
       fFunc->Exec(address);
       fExecuting--;
       if (!TestBit(kNotDeleted) && !fExecuting)
          delete fFunc;
    }

    //______________________________________________________________________________
    inline void TQSlot::ExecuteMethod(void *object, Double_t param)
    {
       // ExecuteMethod the method for the specified object and
       // with single argument value.

       void *address = 0;
       R__LOCKGUARD(gCINTMutex);
       fFunc->ResetArg();
       fFunc->SetArg(param);
       if (object) address = (void*)((Long_t)object + fOffset);
       fExecuting++;
       fFunc->Exec(address);
       fExecuting--;
       if (!TestBit(kNotDeleted) && !fExecuting)
          delete fFunc;
    }

    //______________________________________________________________________________
    inline void TQSlot::ExecuteMethod(void *object, const char *param)
    {
       // ExecuteMethod the method for the specified object and text param.

       void *address = 0;
       gTQSlotParams = (char*)param;
       R__LOCKGUARD(gCINTMutex);
       fFunc->SetArgs("gTQSlotParams");
       if (object) address = (void*)((Long_t)object + fOffset);
       fExecuting++;
       fFunc->Exec(address);
       fExecuting--;
       if (!TestBit(kNotDeleted) && !fExecuting)
          delete fFunc;
    }

    //______________________________________________________________________________
    inline void TQSlot::ExecuteMethod(void *object, Long_t *paramArr, Int_t nparam)
    {
       // ExecuteMethod the method for the specified object and with
       // several argument values.
       // ParamArr is an array containing the function argument values.
       // If nparam = -1 then paramArr must contain values for all function
       // arguments, otherwise Nargs-NargsOpt <= nparam <= Nargs, where
       // Nargs is the number of all arguments and NargsOpt is the number
       // of default arguments.

       void *address = 0;
       R__LOCKGUARD(gCINTMutex);
       fFunc->SetArgArray(paramArr, nparam);
       if (object) address = (void*)((Long_t)object + fOffset);
       fExecuting++;
       fFunc->Exec(address);
       fExecuting--;
       if (!TestBit(kNotDeleted) && !fExecuting)
          delete fFunc;
    }

    //______________________________________________________________________________
    void TQSlot::Print(Option_t *) const
    {
       // Print info about slot.

       cout <<IsA()->GetName() << "t" << GetName() << "t"
       << "Number of Connections = " << References() << endl;
    }

    ////////////////////////////////////////////////////////////////////////////////

    class TQSlotPool : public THashTable {
    public:
       TQSlotPool() : THashTable(50) { }
       virtual ~TQSlotPool() { Delete(); }

       TQSlot  *New(const char *class_name, const char *funcname);
       TQSlot  *New(TClass *cl, const char *method, const char *func);
       void     Free(TQSlot *slot);
    };

    //______________________________________________________________________________
    TQSlot *TQSlotPool::New(const char *class_name, const char *funcname)
    {
       // Create new slot or return already existing one.

       TString name = class_name;
       name += "::";
       name += funcname;

       TQSlot *slot = (TQSlot*)FindObject(name.Data());

       if (!slot) {
          slot = new TQSlot(class_name, funcname);
          Add(slot);
       }
       slot->AddReference();
       return slot;
    }

    //______________________________________________________________________________
    TQSlot *TQSlotPool::New(TClass *cl, const char *method, const char *func)
    {
       // Create new slot or return already existing one.

       TString name;

       if (cl) {
          name = cl->GetName();
          name += "::";
          name += method;
       } else {
          name = "::";
          name += func;
       }

       TQSlot *slot = (TQSlot*)FindObject(name.Data());

       if (!slot) {
          slot = new TQSlot(cl, method, func);
          Add(slot);
       }
       slot->AddReference();
       return slot;
    }

    //______________________________________________________________________________
    void TQSlotPool::Free(TQSlot *slot)
    {
       // Delete slot if there is no refernce to it.

       slot->RemoveReference();  // decrease references to slot

       if (slot->References() <= 0) {
          Remove(slot);
          if (!slot->IsExecuting()) SafeDelete(slot);
       }
    }

    static TQSlotPool gSlotPool;  // global pool of slots

    ////////////////////////////////////////////////////////////////////////////////

    //______________________________________________________________________________
     TQConnection::TQConnection() : TList(), TQObject()
    {
       // Default constructor.

       fReceiver = 0;
       fSlot     = 0;
    }

    //______________________________________________________________________________
     TQConnection::TQConnection(TClass *cl, void *receiver, const char *method_name)
       : TList(), TQObject()
    {
       // TQConnection ctor.
       //    cl != 0  - connection to object == receiver of class == cl
       //               and method == method_name
       //    cl == 0  - connection to function with name == method_name

       char *funcname = 0;
       fReceiver = receiver;      // fReceiver is pointer to receiver

       if (!cl) {
          funcname = G__p2f2funcname(fReceiver);
          if (!funcname)
             Warning("TQConnection", "%s cannot be compiled", method_name);
       }

       if (cl) fClassName = cl->GetName();
       fSlot = gSlotPool.New(cl, method_name, funcname);
    }

    //______________________________________________________________________________
     TQConnection::TQConnection(const char *class_name, void *receiver,
                               const char *funcname) : TList(), TQObject()
    {
       // TQConnection ctor.
       //    Creates connection to method of class specified by name,
       //    it could be interpreted class and with method == funcname.

       fClassName = class_name;
       fSlot = gSlotPool.New(class_name, funcname);  // new slot-method
       fReceiver = receiver;      // fReceiver is pointer to receiver
    }

    //______________________________________________________________________________
     TQConnection::TQConnection(const TQConnection &con): TList(), TQObject()
    {
       // Copy constructor. Ignore connections to this TQConnections

       fClassName = con.fClassName;
       fSlot = con.fSlot;
       fSlot->AddReference();
       fReceiver = con.fReceiver;
    }

    //______________________________________________________________________________
     TQConnection::~TQConnection()
    {
       // TQConnection dtor.
       //    - remove this connection from all signal lists
       //    - we do not delete fSlot if it has other connections,
       //      TQSlot::fCounter > 0 .

       TIter next(this);
       register TList *list;

       while ((list = (TList*)next())) {
          list->Remove(this);
          if (list->IsEmpty()) delete list;   // delete empty list
       }
       Clear("nodelete");

       if (!fSlot) return;
       gSlotPool.Free(fSlot);
    }

    //______________________________________________________________________________
     const char *TQConnection::GetName() const
    {
       // Returns name of connection (aka name of slot)

       return fSlot->GetName();
    }

    //______________________________________________________________________________
     void TQConnection::Destroyed()
    {
       // Signal Destroyed tells that connection is destroyed.

       MakeZombie();
       Emit("Destroyed()");
    }

    //______________________________________________________________________________
     void TQConnection::ls(Option_t *option) const
    {
       // List TQConnection full method name and list all signals
       // connected to this connection.

       cout << "t" <<  IsA()->GetName() << "t" << GetName() << endl;
       ((TQConnection*)this)->ForEach(TList,ls)(option);
    }

    //______________________________________________________________________________
     void TQConnection::Print(Option_t *) const
    {
       // Print TQConnection full method name and print all
       // signals connected to this connection.

       cout <<  "t\tt" << IsA()->GetName() << "t" << fReceiver <<
                "t" << GetName() << endl;
    }

    //______________________________________________________________________________
     void TQConnection::ExecuteMethod()
    {
       // Apply slot-method to the fReceiver object without arguments.

       // This connection might be deleted in result of the method execution
       // (for example in case of a Disconnect).  Hence we do not assume
       // the object is still valid on return.
       TQSlot *s = fSlot;
       fSlot->ExecuteMethod(fReceiver);
       if (s->References() <= 0) delete s;
    }

    //______________________________________________________________________________
     void TQConnection::ExecuteMethod(Long_t param)
    {
       // Apply slot-method to the fReceiver object with
       // single argument value.

       // This connection might be deleted in result of the method execution
       // (for example in case of a Disconnect).  Hence we do not assume
       // the object is still valid on return.
       TQSlot *s = fSlot;
       fSlot->ExecuteMethod(fReceiver, param);
       if (s->References() <= 0) delete s;
    }

    //______________________________________________________________________________
     void TQConnection::ExecuteMethod(Double_t param)
    {
       // Apply slot-method to the fReceiver object with
       // single argument value.

       // This connection might be deleted in result of the method execution
       // (for example in case of a Disconnect).  Hence we do not assume
       // the object is still valid on return.
       TQSlot *s = fSlot;
       fSlot->ExecuteMethod(fReceiver, param);
       if (s->References() <= 0) delete s;
    }

    //______________________________________________________________________________
     void TQConnection::ExecuteMethod(Long_t *params, Int_t nparam)
    {
       // Apply slot-method to the fReceiver object with variable
       // number of argument values.

       // This connection might be deleted in result of the method execution
       // (for example in case of a Disconnect).  Hence we do not assume
       // the object is still valid on return.
       TQSlot *s = fSlot;
       fSlot->ExecuteMethod(fReceiver, params, nparam);
       if (s->References() <= 0) delete s;
    }

    //______________________________________________________________________________
     void TQConnection::ExecuteMethod(const char *param)
    {
       // Apply slot-method to the fReceiver object and
       // with string parameter.

       // This connection might be deleted in result of the method execution
       // (for example in case of a Disconnect).  Hence we do not assume
       // the object is still valid on return.
       TQSlot *s = fSlot;
       fSlot->ExecuteMethod(fReceiver, param);
       if (s->References() <= 0) delete s;
    }