Q64786: _pg_chartpie() Fails to Free Memory in QC 2.00 and QC 2.50

Article: Q64786
Product(s): See article
Version(s): 2.00 2.50
Operating System(s): MS-DOS
Keyword(s): ENDUSER | buglist2.50 | mspl13_c
Last Modified: 17-DEC-1990

The presentation graphics function _pg_chartpie() fails to return
memory allocated from DOS.

Successive calls to _pg_chartpie() will cause three paragraphs of
memory to be allocated from DOS for each call. Because there is no
companion to _pg_initchart() [for example, _pg_closechart()], the
memory allocated by _pg_chartpie() is not returned to DOS until the
program finishes execution.

The program below demonstrates this problem.

Sample Code
-----------

#include <stdlib.h>
#include <graph.h>
#include <pgchart.h>
#include <stdio.h>

#define COUNTRIES 5
float _far value[COUNTRIES] = { 42.5F,  14.3F, 35.2F,  21.3F,
                                32.6F   };
char  _far *category[COUNTRIES] = { "USSR", "GDR", "USA",  "UK",
                                    "Other" };
short _far explode[COUNTRIES] =   { 0,      1,     0,      1,     0 };

void main()
{
    char stringbuff[80];
    chartenv env;
    unsigned sized=0;
    unsigned seg=0;
    /* Get Dos Memory Available on far heap-wait for key hit */
    _settextposition(4,4);
    _dos_allocmem(0xffff,&seg);
    sprintf(stringbuff,"Memory : %u\n",seg);
    _outtext(stringbuff);

    getch();
    if( !_setvideomode( _VRES16COLOR ) )
        exit( 1 );

    _pg_initchart(); /* Initialize chart system    */

    while(1)
        {

    /* Pie chart */

        _pg_defaultchart( &env, _PG_PIECHART, _PG_PERCENT );
        strcpy( env.maintitle.title, "Widget Production" );
        _pg_chartpie( &env, category, value, explode, COUNTRIES );

    /* Display available memory- wait for key hit */

        _settextposition(4,4);
        _dos_allocmem(0xffff,&seg);
        sprintf(stringbuff,"Memory : %u\n",seg);
        _outtext(stringbuff);
        getch();

    }
    _setvideomode( _DEFAULTMODE );
}

Microsoft has confirmed this to be a problem in QuickC version 2.50.
We are researching this problem and will post new information here as
it becomes available.

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