RexxVariable.cpp

Go to the documentation of this file.

/*----------------------------------------------------------------------------*/
/*                                                                            */
/* Copyright (c) 1995, 2004 IBM Corporation. All rights reserved.             */
/* Copyright (c) 2005-2009 Rexx Language Association. All rights reserved.    */
/*                                                                            */
/* This program and the accompanying materials are made available under       */
/* the terms of the Common Public License v1.0 which accompanies this         */
/* distribution. A copy is also available at the following address:           */
/* http://www.oorexx.org/license.html                          */
/*                                                                            */
/* Redistribution and use in source and binary forms, with or                 */
/* without modification, are permitted provided that the following            */
/* conditions are met:                                                        */
/*                                                                            */
/* Redistributions of source code must retain the above copyright             */
/* notice, this list of conditions and the following disclaimer.              */
/* Redistributions in binary form must reproduce the above copyright          */
/* notice, this list of conditions and the following disclaimer in            */
/* the documentation and/or other materials provided with the distribution.   */
/*                                                                            */
/* Neither the name of Rexx Language Association nor the names                */
/* of its contributors may be used to endorse or promote products             */
/* derived from this software without specific prior written permission.      */
/*                                                                            */
/* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS        */
/* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT          */
/* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS          */
/* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT   */
/* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,      */
/* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED   */
/* TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA,        */
/* OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY     */
/* OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING    */
/* NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS         */
/* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.               */
/*                                                                            */
/*----------------------------------------------------------------------------*/
/****************************************************************************/
/* REXX Kernel                                           RexxVariable.c     */
/*                                                                          */
/* Primitive Variable Class                                                 */
/*                                                                          */
/****************************************************************************/
#include "RexxCore.h"
#include "RexxVariable.hpp"
#include "RexxActivity.hpp"
#include "ActivityManager.hpp"
 
void RexxVariable::live(size_t liveMark)
/******************************************************************************/
/* Function:  Normal garbage collection live marking                          */
/******************************************************************************/
{
  memory_mark(this->variableValue);
  memory_mark(this->variable_name);
  memory_mark(this->dependents);
}
 
void RexxVariable::liveGeneral(int reason)
/******************************************************************************/
/* Function:  Normal garbage collection live marking                          */
/******************************************************************************/
{
  memory_mark_general(this->variableValue);
  memory_mark_general(this->variable_name);
  memory_mark_general(this->dependents);
}
 
void RexxVariable::flatten(RexxEnvelope *envelope)
/******************************************************************************/
/* Function:  Flatten an object                                               */
/******************************************************************************/
{
  setUpFlatten(RexxVariable)
 
   flatten_reference(newThis->variableValue, envelope);
   flatten_reference(newThis->variable_name, envelope);
   flatten_reference(newThis->dependents, envelope);
 
  cleanUpFlatten
}
 
void RexxVariable::inform(
     RexxActivity *informee)           /* activity to inform of changes     */
/****************************************************************************/
/* Function:  Set up an activity notification for a variable change         */
/****************************************************************************/
{
    if (this->dependents == OREF_NULL)   /* no dependents yet?                */
    {
        /* set this up as an object table    */
        OrefSet(this, this->dependents, new_identity_table());
    }
    /* add this to the table             */
    this->dependents->put(TheNilObject, (RexxObject *)informee);
}
 
void RexxVariable::uninform(
     RexxActivity *informee)           /* activity to inform of changes     */
/****************************************************************************/
/* Function:  Remove a dependent from the notification list                 */
/****************************************************************************/
{
    /* remove the entry                  */
    this->dependents->remove((RexxObject *)informee);
    if (this->dependents->items() == 0)  /* last one?                         */
    {
        /* drop the dependents list          */
        OrefSet(this, this->dependents, OREF_NULL);
    }
}
 
void RexxVariable::drop()
/****************************************************************************/
/* Function:  Drop a variable                                               */
/****************************************************************************/
{
    /* clear out the value               */
    OrefSet(this, this->variableValue, OREF_NULL);
    if (this->dependents != OREF_NULL)   /* have notifications to process?    */
    {
        this->notify();                    /* notify any dependents             */
    }
}
 
void RexxVariable::notify()
/****************************************************************************/
/* Function:  Process all variable notifications                            */
/****************************************************************************/
{
    if (this->dependents != OREF_NULL)
    { /* any dependents?                   */
      /* loop through the table            */
        for (HashLink i = this->dependents->first(); this->dependents->available(i); i = this->dependents->next(i))
        {
            /* post the event to the dependent   */
            ((RexxActivity *)this->dependents->index(i))->guardPost();
        }
        /* yield control and allow the       */
        /* waiting guard to run too          */
        /* get the current activity          */
        RexxActivity *activity = ActivityManager::currentActivity;
        activity->releaseAccess();         /* release the lock                  */
        activity->requestAccess();         /* get it back again                 */
    }
}
 
 
RexxVariable *RexxVariable::newInstance(
    RexxString *name)                  /* the name of the variable          */
/****************************************************************************/
/* Function:  Create a new REXX variable object                             */
/****************************************************************************/
{
    /* Get new object                    */
    RexxVariable *newObj = (RexxVariable *)new_object(sizeof(RexxVariable), T_Variable);
    newObj->variableValue = OREF_NULL;   /* clear out the hash value          */
    newObj->creator = OREF_NULL;         /* clear out creator field           */
    newObj->variable_name = name;        /* fill in the name                  */
    newObj->dependents = OREF_NULL;      /* and the dependents                */
    return newObj;                       /* return the new object             */
}