Memory leak when using mglGraphPS

[Nobody/Anonymous]

Hi.
First of all, thank you for making this very nice plotting library.
It works fine and makes plots without problems, but there seems to be a memory
leak.
As I intend to use this in a program that will run for days/weeks/longer and
automatically produce plots,
I cannot have memory leaks.
I made a small test case that replicates the problem:

So, am I using MathGL wrong, or is there a bug in the mglGraph memory
handling?

Source code (file "testingMathGL.cpp"):

include <cstdlib> // For atoi()

// MathGL

include "mgl/mgl.h"

include "mgl/mgl_eps.h"

include "mgl/mgl_zb.h"

void testingMathGL()
{
mglGraphPS postscriptPlot;

unsigned int i, j;
unsigned int longs = 100, lats = 100;

// Set up data containers
mglData VTECData(longs, lats), GIVEData(longs, lats), lon(longs), lat(lats);

// Insert dummy data
for(i = 0; i <= longs; i++) {
for(j = 0; j <= lats; j++) {
double VTEC = 2;
VTECData.Put(VTEC, i, j);

double GIVE = 3;
GIVEData.Put(GIVE, i, j);
}
}
for(i = 0; i <= longs; i++) lon.Put(i, i);
for(j = 0; j <= lats; j++) lat.Put(j, j);

// Clear plot
postscriptPlot.Clf();

// Set up plot
postscriptPlot.CAxis(0, 4);
postscriptPlot.XRange(lon);
postscriptPlot.YRange(lat);

// Plot panel 1
postscriptPlot.SubPlot(1,2,0);
postscriptPlot.Dens(VTECData);
postscriptPlot.Axis();
postscriptPlot.Box();
postscriptPlot.Colorbar(0, 0.9, 0, 0.8, 1);
postscriptPlot.Label('x', "Longitude (degrees)", 0);
postscriptPlot.Label('y', "Latitude (degrees)", 0);
postscriptPlot.Puts(mglPoint(0.95, 0.45), "VTEC (m)", "a", 6);
postscriptPlot.Title("TestTitle", "", 4);

// Plot panel 2
postscriptPlot.SubPlot(1,2,1);
postscriptPlot.Dens(GIVEData);
postscriptPlot.Axis();
postscriptPlot.Box();
postscriptPlot.Colorbar(0, 0.9, 0, 0.8, 1);
postscriptPlot.Label('x', "Longitude (degrees)", 0);
postscriptPlot.Label('y', "Latitude (degrees)", 0);
postscriptPlot.Puts(mglPoint(0.95, 0.45), "GIVE (m)", "a", 6);

// Write to file
postscriptPlot.WriteEPS("test.eps");
}

int main(int argc, char ** argv)
{
unsigned int i = 0;
unsigned int maxi = atoi(argv);

while(i < maxi) {
testingMathGL();
i++;
}

return 0;
}

Compile command:

g++ testingMathGL.cpp -O0 -g3 -Wall -Wextra -Wconversion -Wshadow -lmgl -o
testingMathGL

valgrind command:

valgrind --leak-check=full ./testingMathGL 1

valgrind output:

==6083== Memcheck, a memory error detector
==6083== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al.
==6083== Using Valgrind-3.5.0 and LibVEX; rerun with -h for copyright info
==6083== Command: ./testingMathGL 1
==6083==
==6083== Mismatched free() / delete / delete
==6083== at 0x4A04700: operator delete(void) (vg_replace_malloc.c:368)
==6083== by 0x3C4B05BC42: mglGraphPS::~mglGraphPS() (in
/usr/lib64/libmgl.so.5.0.0)
==6083== by 0x401337: testingMathGL() (testingMathGL.cpp:63)
==6083== by 0x4013EC: main (testingMathGL.cpp:72)
==6083== Address 0x5c3c040 is 0 bytes inside a block of size 2,300,000 alloc'd
==6083== at 0x4A05255: realloc (vg_replace_malloc.c:476)
==6083== by 0x3C4B05B874: mglGraphPS::add_prim(mglPrim&) (in
/usr/lib64/libmgl.so.5.0.0)
==6083== by 0x3C4B05E06C: mglGraphPS::Glyph(float, float, float, int, long,
char) (in /usr/lib64/libmgl.so.5.0.0)
==6083== by 0x3C4B060D39: mglFont::Puts(unsigned int const, float, float,
float, int, char) (in /usr/lib64/libmgl.so.5.0.0)
==6083== by 0x3C4B062460: mglFont::Puts(wchar_t const, int, int, char) (in
/usr/lib64/libmgl.so.5.0.0)
==6083== by 0x3C4B0EB0A1: mglGraphAB::Putsw(mglPoint, wchar_t const, char
const, float, char, float) (in /usr/lib64/libmgl.so.5.0.0)
==6083== by 0x3C4B0B2B80: mglGraph::Label(char, char const, float, float,
float) (in /usr/lib64/libmgl.so.5.0.0)
==6083== by 0x40123C: testingMathGL() (testingMathGL.cpp:58)
==6083== by 0x4013EC: main (testingMathGL.cpp:72)
==6083==
==6083==
==6083== HEAP SUMMARY:
==6083== in use at exit: 960,000 bytes in 1 blocks
==6083== total heap usage: 350 allocs, 349 frees, 32,632,194 bytes allocated
==6083==
==6083== 960,000 bytes in 1 blocks are definitely lost in loss record 1 of 1
==6083== at 0x4A055EC: operator new(unsigned long) (vg_replace_malloc.c:264)
==6083== by 0x3C4B0E8858: mglGraphAB::SetSize(int, int) (in
/usr/lib64/libmgl.so.5.0.0)
==6083== by 0x3C4B0EC198: mglGraphAB::mglGraphAB(int, int) (in
/usr/lib64/libmgl.so.5.0.0)
==6083== by 0x3C4B05BC78: mglGraphPS::mglGraphPS(int, int) (in
/usr/lib64/libmgl.so.5.0.0)
==6083== by 0x400D9A: testingMathGL() (testingMathGL.cpp:12)
==6083== by 0x4013EC: main (testingMathGL.cpp:72)
==6083==
==6083== LEAK SUMMARY:
==6083== definitely lost: 960,000 bytes in 1 blocks
==6083== indirectly lost: 0 bytes in 0 blocks
==6083== possibly lost: 0 bytes in 0 blocks
==6083== still reachable: 0 bytes in 0 blocks
==6083== suppressed: 0 bytes in 0 blocks
==6083==
==6083== For counts of detected and suppressed errors, rerun with: -v
==6083== ERROR SUMMARY: 2 errors from 2 contexts (suppressed: 6 from 6)

MathGL version:

$ yum list installed | grep mathgl
mathgl.i686 1.10.2.1-3.fc13 @updates
mathgl.x86_64 1.10.2.1-3.fc13 @updates
mathgl-devel.i686 1.10.2.1-3.fc13 @updates
mathgl-devel.x86_64 1.10.2.1-3.fc13 @updates

[Nobody/Anonymous]

Hi.
I've now downloaded and compiled the newest version (1.11.0.1).
(Which was made a little complicated because I had to compile it myself as a
32-bit library on a 64-bit machine)

I ran the test again, and this time there were no errors:

==27246== Memcheck, a memory error detector
==27246== Copyright (C) 2002-2009, and GNU GPL'd, by Julian Seward et al.
==27246== Using Valgrind-3.5.0 and LibVEX; rerun with -h for copyright info
==27246== Command: ./testingMathGL 1
==27246==
==27246==
==27246== HEAP SUMMARY:
==27246== in use at exit: 0 bytes in 0 blocks
==27246== total heap usage: 77 allocs, 77 frees, 23,864,456 bytes allocated
==27246==
==27246== All heap blocks were freed -- no leaks are possible
==27246==
==27246== For counts of detected and suppressed errors, rerun with: -v
==27246== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 6 from 6)

So if anyone else is having memory issues, try updating to a newer build.