[geos-devel] problems with C/C++- getting warmer! (Reader Frees too much?)

[David Blasby]

Norman,

    Could you give this little C++ code a try?  Then try it again 
without the "delete r;  delete w;" lines commented out.
On my linux system, it works with the 2 lines commented out, but fails 
with them actually in.  More specficially it
fails if the reader (r) is deleted.  

My bet is that the reader is freeing too much (perhaps the 
PrecisionModel?).  The difference is functinality is probably
how cygwin actually implements its deletes at the operating system 
level.  I know that solaris machines are really picky about
memory allocations and deletions - more so than linux machines.  Perhaps 
linux is more picky than cygwin?

I'll look in the actual geos code, but I wanted to know what happens on 
your system.


 [dblasby at lion work_dave]$ g++ test.cpp -I/usr/local/include/geos -lgeos 
; ./a.out
geom (WKTWriter first try (should work) ):POLYGON ((100.0000000000000000 
200.0000000000000000, 100.0000000000000000 140.0000000000000000, 
180.0000000000000000 140.0000000000000000, 180.0000000000000000 
200.0000000000000000, 100.0000000000000000 200.0000000000000000))

geom (WKTWriter):POLYGON ((100.0000000000000000 200.0000000000000000, 
100.0000000000000000 140.0000000000000000, 180.0000000000000000 
140.0000000000000000, 180.0000000000000000 200.0000000000000000, 
100.0000000000000000 200.0000000000000000))
[dblasby at lion work_dave]$ cat test.cpp
// g++ test.cpp -I/usr/local/include/geos -lgeos

#include "stdio.h"
#include "io.h"


int main(int argC, char* argV[])
{

    Geometry *g = new Geometry;
    WKTReader *r = new WKTReader(new GeometryFactory(new 
PrecisionModel(),-1));
    WKTWriter *w=new WKTWriter();
    string wkt_out;


    g = r->read("POLYGON((100 200,100 140,180 140,180 200,100 200))");

    wkt_out =  w->write(g) ;

        cout << endl << "geom (WKTWriter first try (should work) ):"<< 
wkt_out << endl;

    //delete r;       //uncommenting this will cause this program to 
fail on linux machines.
    //delete w;

    w=new WKTWriter();
    wkt_out =  w->write(g) ;

    cout << endl << "geom (WKTWriter):"<< wkt_out << endl;


}