XrdObject.hh

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#ifndef __XRD_OBJECT_H__
#define __XRD_OBJECT_H__
/******************************************************************************/
/*                                                                            */
/*                          X r d O b j e c t . h h                           */
/*                                                                            */
/*(c) 2004 by the Board of Trustees of the Leland Stanford, Jr., University   */
/*       All Rights Reserved. See XrdInfo.cc for complete License Terms       */
/*Produced by Andrew Hanushevsky for Stanford University under contract       */
/*           DE-AC03-76-SFO0515 with the Deprtment of Energy                  */
/******************************************************************************/

//         $Id$

#include <string.h>
#include <strings.h>
#include <time.h>
#include <sys/types.h>

#include "Xrd/XrdJob.hh"

// The classes here are templates for singly linked list handling that allows
// elements to be added to either end but be removed only from the front. Most
// objects in this package are managed in queues of this type.
  
/******************************************************************************/
/*                            x r d _ O b j e c t                             */
/******************************************************************************/

template <class T>
class XrdObjectQ;
  
template <class T>
class XrdObject
{
public:
friend class XrdObjectQ<T>;


// Item() supplies the item value associated with itself (used with Next()).
//
T             *objectItem() {return Item;}

// Next() supplies the next list node.
//
XrdObject<T> *nextObject() {return Next;}

// Set the item pointer
//
void           setItem(T *ival) {Item = ival;}

               XrdObject(T *ival=0) {Next = 0; Item = ival; QTime = 0;}
              ~XrdObject() {}

private:
XrdObject<T> *Next;
T             *Item;
time_t         QTime;  // Only used for time-managed objects
};

/******************************************************************************/
/*                           x r d _ O b j e c t Q                            */
/******************************************************************************/
  
// Note to properly cleanup this type of queue you must call Set() at least
// once to cause the time element to be sceduled.

class XrdOucTrace;
class XrdScheduler;
  
template <class T>
class XrdObjectQ : public XrdJob
{
public:

inline T      *Pop() {XrdObject<T> *Node;
                      QMutex.Lock();
                      if ((Node = First)) {First = First->Next; Count--;}
                      QMutex.UnLock();
                      if (Node) return Node->Item;
                      return (T *)0;
                     }

inline void    Push(XrdObject<T> *Node)
                     {Node->QTime = Curage;
                      QMutex.Lock();
                      if (Count >= MaxinQ) delete Node->Item;
                         else {Node->Next = First;
                               First = Node;
                               Count++;
                              }
                      QMutex.UnLock();
                     }

       void    Set(int inQMax, time_t agemax=1800);

       void    Set(XrdScheduler *sp, XrdOucTrace *tp, int TraceChk=0)
                      {Sched = sp; Trace = tp; TraceON = TraceChk;}

       void    DoIt();

       XrdObjectQ(const char *id, const char *desc) : XrdJob(desc)
                  {Curage = Count = 0; Maxage = 0; TraceID = id;
                   MaxinQ = 32; MininQ = 16; First = 0;
                  }

      ~XrdObjectQ() {}

private:

XrdSysMutex    QMutex;
XrdObject<T>  *First;
int            Count;
int            Curage;
int            MininQ;
int            MaxinQ;
time_t         Maxage;
XrdScheduler  *Sched;
XrdOucTrace   *Trace;
int            TraceON;
const char    *TraceID;
};

#include "Xrd/XrdObject.icc"
#endif