[plt-scheme] Problem embedding scheme in real time application.

Hello,

I'm trying use mzScheme for a realtime application in C++ using Visual
Studio 8.0. I wrapped the scheme setup in a class (and this is
probably where I'm having problems). Here's a small main loop:


#include <iostream>

#include "SchemeInterface.h"
#include <string>

void main(int argc, char *argv[]) {

	SchemeInterface sh;
	sh.evaluate("(define test 'test)");
	bool exit = false;

	while(!exit) {
		sh.evaluate("test");
	}
}

This will run for a short while and then crash out with an access
violation error. So it seems I'm writing or reading somewhere I
shouldn't.

Here's my class file. I hope someone can point, my mistake

Thank you,
Dan

//
// Header
//
#pragma once

#define MZ_PRECISE_GC

#include <string>
#include "scheme.h"

class SchemeInterface
{
private:
	Scheme_Env *e;
	Scheme_Object *curout, *v;
	Scheme_Config *config;

	mz_jmp_buf * volatile save, fresh;
	
public:
	SchemeInterface(void);
	~SchemeInterface(void);

	Scheme_Object * evaluate(const std::string& expression);

};

//
// CPP file
//
#include "SchemeInterface.h"
#include <iostream>


// Creates gc_var_stack
MZ_GC_DECL_REG(5);

SchemeInterface::SchemeInterface(void) {
	
	e = NULL;
	curout = NULL;
	v = NULL;
	config = NULL;

	save = NULL;

	MZ_GC_DECL_REG(5);
	MZ_GC_VAR_IN_REG(0, e);
	MZ_GC_VAR_IN_REG(1, curout);
	MZ_GC_VAR_IN_REG(2, save);
	MZ_GC_VAR_IN_REG(3, config);
	MZ_GC_VAR_IN_REG(4, v);

	# ifdef MZ_PRECISE_GC
	#  define STACK_BASE &__gc_var_stack__
	# else
	#  define STACK_BASE NULL
	# endif

	scheme_set_stack_base(STACK_BASE, 1);

	MZ_GC_REG();

	e = scheme_basic_env();

	config = scheme_current_config();
	curout = scheme_get_param(config, MZCONFIG_OUTPUT_PORT);
}

SchemeInterface::~SchemeInterface(void) {
	MZ_GC_UNREG();
}

Scheme_Object * SchemeInterface::evaluate(const std::string& expression){

	Scheme_Object * v = 0;
	 v = scheme_eval_string(expression.c_str(), e);

	// std::cout << "Output type:" << v->type << std::endl;

	 scheme_display(v, curout);
	 scheme_flush_output(curout);
	 return v;
}



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