VM.h

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// VM.h: the Virtual Machine class, for Gnash
// 
//   Copyright (C) 2005, 2006, 2007, 2008, 2009, 2010 Free Software
//   Foundation, Inc
// 
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 3 of the License, or
// (at your option) any later version.
// 
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
// 
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

#ifndef GNASH_VM_H
#define GNASH_VM_H

#ifdef HAVE_CONFIG_H
#include "gnashconfig.h"
#endif

#include <map>
#include <vector>
#include <memory> 
#include <locale>
#include <boost/cstdint.hpp> 
#include <boost/random.hpp>
#include <boost/noncopyable.hpp>
#include <boost/intrusive_ptr.hpp>
#include <boost/array.hpp>

#include "GC.h"
#include "string_table.h"
#include "SafeStack.h"
#include "CallStack.h"
#include "smart_ptr.h"
#include "as_value.h"

// Forward declarations
namespace gnash {
        class Global_as;
        class VM;
        class fn_call;
        class movie_root;
        class NativeFunction;
    class SharedObjectLibrary;
        class as_value;
        class as_object;
        class VirtualClock;
    class UserFunction;
}

namespace gnash {

class VmGcRoot : public GcRoot 
{
public:
        VmGcRoot(VM& vm) : _vm(vm) {}
        virtual void markReachableResources() const;

private:
    VM& _vm;
};

//
//
//
//
//
class DSOEXPORT VM : boost::noncopyable
{

public:

        typedef as_value (*as_c_function_ptr)(const fn_call& fn);

        //
        static VM& init(int version, movie_root& root, VirtualClock& clock);

        SafeStack<as_value>& getStack() {
                return _stack;
        }

    //
    VirtualClock& getClock() {
        return _clock;
    }

        static bool isInitialized();

    //
    void clear();

        //
        static VM& get();

        //
        int getSWFVersion() const;

        void setSWFVersion(int v);

        unsigned long int getTime() const;

        string_table& getStringTable() const { return _stringTable; }

        //
        const std::string& getPlayerVersion() const;
        
        const std::string getOSName();
        
        const std::string getSystemLanguage();
        
        // The boost Random Number Generator to use.
        //
        // http://www.boost.org/libs/random/random-generators.html
        //
        // TODO: boost/nondet_random.hpp provides access to a random device,
        // which can be used in preference to a pseudo-RNG. It is only
        // presently available on some platforms.
        // http://www.boost.org/libs/random/nondet_random.html
        //
        // Generators have different limits on the size of the seed. Please
        // check if replacing the generator.
        //
        // The mt11213b provides a pseudo-random number cycle
        // of length 2^11213-1 and requires approx 352*sizeof(uint32_t) memory
        // once initialized. It is more than adequate for most purposes.
        typedef boost::mt11213b RNG;    

        // Get a pointer to the random number generator for
        // use by Math.random() and random().
        //
        // The seed is the system time in milliseconds at the first call
        // to a random function. This allows a potentially variable amount
        // of time to elapse between starting gnash and initialization of
        // the generator, so decreasing predictability.
        RNG& randomNumberGenerator() const;

        movie_root& getRoot() const;

    //
    SharedObjectLibrary& getSharedObjectLibrary() const {
        assert(_shLib.get());
        return *_shLib;
    }

        Global_as* getGlobal() const;

        //
        void markReachableResources() const;

        void registerNative(as_c_function_ptr fun, unsigned int x, unsigned int y);

        NativeFunction* getNative(unsigned int x, unsigned int y) const;

    //
    //
    const as_value* getRegister(size_t index);

    //
    void setRegister(size_t index, const as_value& val);

    //
    //
    CallFrame& pushCallFrame(UserFunction& f);

    //
    void popCallFrame();

    //
    CallFrame& currentCall();

    bool calling() const {
        return !_callStack.empty();
    }

    void dumpState(std::ostream& o, size_t limit = 0);

#ifdef GNASH_USE_GC
        void addStatic(GcResource* res)
        {
                _statics.push_back(res);
        }
#else  // ndef GNASH_USE_GC
        // placeholder to avoid adding lots of
        // compile-time switches in callers
        void addStatic(as_object*) {}
#endif

private:

        friend class VmGcRoot;

        //
        VM(int version, movie_root& root, VirtualClock& clock);

        ~VM();

        // We use an auto_ptr here to allow constructing
        // the singleton when the init() function is called.
        friend class std::auto_ptr<VM>;
        static std::auto_ptr<VM> _singleton;

        movie_root& _rootMovie;

        Global_as* _global;

        int _swfversion;

        //
        void setGlobal(Global_as*);

#ifdef GNASH_USE_GC


        //
        typedef std::vector< boost::intrusive_ptr<GcResource> > ResVect;
        ResVect _statics;
#endif

        typedef std::map<unsigned int, as_c_function_ptr> FuncMap;
        typedef std::map<unsigned int, FuncMap> AsNativeTable;
        AsNativeTable _asNativeTable;

        mutable string_table _stringTable;

        VirtualClock& _clock;

        SafeStack<as_value>     _stack;

    typedef boost::array<as_value, 4> GlobalRegisters;
    GlobalRegisters _globalRegisters;

        CallStack _callStack;

    std::auto_ptr<SharedObjectLibrary> _shLib;

};

class FrameGuard
{
public:

    FrameGuard(VM& vm, UserFunction& func)
        :
        _vm(vm),
        _callFrame(_vm.pushCallFrame(func))
    {
    }

    CallFrame& callFrame() {
        return _callFrame;
    }

    ~FrameGuard() {
        _vm.popCallFrame();
    }

private:
    VM& _vm;
    CallFrame& _callFrame;
};


//
//
void newAdd(as_value& op1, const as_value& op2, VM& vm);

//
void subtract(as_value& op1, const as_value& op2, VM& vm);

//
as_value newLessThan(const as_value& op1, const as_value& op2, VM& vm);

} // namespace gnash

#endif // GNASH_VM_H

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