rtt.cpp

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/*
 * Lua-RTT bindings
 *
 * (C) Copyright 2010 Markus Klotzbuecher
 * markus.klotzbuecher@mech.kuleuven.be
 * Department of Mechanical Engineering,
 * Katholieke Universiteit Leuven, Belgium.
 *
 * This library 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;
 * version 2 of the License.
 *
 * As a special exception, you may use this file as part of a free
 * software library without restriction.  Specifically, if other files
 * instantiate templates or use macros or inline functions from this
 * file, or you compile this file and link it with other files to
 * produce an executable, this file does not by itself cause the
 * resulting executable to be covered by the GNU General Public
 * License.  This exception does not however invalidate any other
 * reasons why the executable file might be covered by the GNU General
 * Public License.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place,
 * Suite 330, Boston, MA  02111-1307  USA
 */

#include "rtt.hpp"

using namespace std;
using namespace RTT;
using namespace RTT::detail;
using namespace RTT::base;
using namespace RTT::internal;

static TaskContext* __getTC(lua_State*);

#define DEBUG

#ifdef DEBUG
# define _DBG(fmt, ...) printf("%s:%d\t" fmt "\n", __FUNCTION__, __LINE__, __VA_ARGS__)
#else
# define _DBG(fmt, ...) do { } while(0)
#endif

/*
 * Inspired by tricks from here: http://lua-users.org/wiki/DoItYourselfCppBinding
 */

/* overloading new */
void* operator new(size_t size, lua_State* L, const char* mt)
{
        void* ptr = lua_newuserdata(L, size);
        luaL_getmetatable(L, mt);
        /* assert(lua_istable(L, -1)) */  /* if you're paranoid */
        lua_setmetatable(L, -2);
        return ptr;
}

/*
 * luaM_pushobject_mt(L, "Port", InputPortInterface )(ctr_arg,...)
 * expands to
 * new(L, "Port") InputPortInterface(ctr_arg,...)
 */

#define luaM_pushobject(L, T) new(L, #T) T
#define luaM_pushobject_mt(L, MT, T) new(L, MT) T

/* return udata ptr or fail if wrong metatable */
#define luaM_checkudata(L, pos, T) reinterpret_cast<T*>(luaL_checkudata((L), (pos), #T))
#define luaM_checkudata_mt(L, pos, MT, T) reinterpret_cast<T*>(luaL_checkudata((L), (pos), MT))

/* return udata ptr or NULL if wrong metatable */
#define luaM_testudata(L, pos, T) (T*) (luaL_testudata((L), (pos), #T))
#define luaM_testudata_mt(L, pos, MT, T) (T*) (luaL_testudata((L), (pos), MT))

/*
 * boxed variants
 */

/* return boxed udata ptr or fail if wrong metatable */
#define luaM_checkudata_bx(L, pos, T) (T**) (luaL_checkudata((L), (pos), #T))
#define luaM_checkudata_mt_bx(L, pos, MT, T) (T**) (luaL_checkudata((L), (pos), MT))

/* return udata ptr or NULL if wrong metatable */
#define luaM_testudata_bx(L, pos, T) (T**) (luaL_testudata((L), (pos), #T))
#define luaM_testudata_mt_bx(L, pos, MT, T) (T**) (luaL_testudata((L), (pos), MT))

/* generate a function to push boxed pointers to lua */
#define gen_push_bxptr(name, MT, T)                        \
static void name(lua_State *L, T* ptr)                     \
{                                                          \
        T** ptrptr = (T**) lua_newuserdata(L, sizeof(T*)); \
        *ptrptr = ptr;                                     \
        luaL_getmetatable(L, MT);                          \
        lua_setmetatable(L, -2);                           \
}                                                          \

/* template for generating GC function */
template<typename T>
int GCMethod(lua_State* L)
{
        reinterpret_cast<T*>(lua_touserdata(L, 1))->~T();
        return 0;
}


/***************************************************************
 * Some generic helpers
 ***************************************************************/

/* test if userdata on position ud has metatable tname */
void* luaL_testudata (lua_State *L, int ud, const char *tname)
{
        void *p = lua_touserdata(L, ud);

        if (p == NULL)
                goto out;

        if (!lua_getmetatable(L, ud))  {
                p = NULL;
                goto out;
        }

        /* it has a MT, is it the right one? */
        lua_pushstring(L, tname);
        lua_rawget(L, LUA_REGISTRYINDEX);

        if (!lua_rawequal(L, -1, -2))
                p = NULL;

        lua_pop(L, 2);  /* remove both metatables */
 out:
        return p;
}


void push_vect_str(lua_State *L, const std::vector<std::string> &v)
{
        int key = 1;
        lua_createtable(L, v.size(), 0);

        for(vector<std::string>::const_iterator it = v.begin(); it != v.end(); ++it) {
                lua_pushstring(L, it->c_str());
                lua_rawseti(L, -2, key++);
        }
}

/* forw decl */
static void Variable_fromlua(lua_State *L, DataSourceBase::shared_ptr& dsb, int valind);
static DataSourceBase::shared_ptr Variable_fromlua(lua_State *L, const types::TypeInfo* ti, int valind);
static DataSourceBase::shared_ptr Variable_fromlua(lua_State *L, const char* type, int valind);

/***************************************************************
 * Variable (DataSourceBase)
 ***************************************************************/

static const TypeInfo* ti_lookup(lua_State *L, const char *name)
{
#ifndef TYPEINFO_CACHING
        return types::TypeInfoRepository::Instance()->type(name);
#else
/* name-> TypeInfo* cache */
        int top = lua_gettop(L);
        const TypeInfo* ti;

        /* try lookup */
        lua_pushstring(L, "typeinfo_cache");
        lua_rawget(L, LUA_REGISTRYINDEX);

        if(lua_type(L, -1) == LUA_TTABLE)
                goto table_on_top;

        /* first lookup, create table */
        lua_pop(L, 1); /* pop nil */
        lua_newtable(L); /* stays on top after the next three lines */
        lua_pushstring(L, "typeinfo_cache"); /* key */
        lua_pushvalue(L, -2); /* duplicates table */
        lua_rawset(L, LUA_REGISTRYINDEX);       /* REG['typeinfo_cache']={} */

 table_on_top:
        /* try to lookup name in table */
        lua_pushstring(L, name);
        lua_rawget(L, -2);

        if(lua_type(L, -1) != LUA_TLIGHTUSERDATA)
                goto cache_miss;

        ti = (const TypeInfo*) lua_touserdata(L, -1);
        goto out;

 cache_miss:
        lua_pop(L, 1); /* pop the nil */
        ti = types::TypeInfoRepository::Instance()->type(name);
        if (ti) { // only save if type exists !
                lua_pushstring(L, name);
                lua_pushlightuserdata(L, (void*) ti);
                lua_rawset(L, -3);
        }
 out:
        /* everyone happy! */
        lua_settop(L, top);
        return ti;
#endif /* TYPEINFO_CACHING */
}

/* helper, check if a type name is an alias to the given TypeInfo */
static bool __typenames_cmp(lua_State *L, const types::TypeInfo *ti1, const char* type2)
{
        const types::TypeInfo *ti2 = ti_lookup(L, type2);
        return ti1 == ti2;
}

/* helper, check if a dsb is of type type. Works also if dsb is known
   under an alias of type */
static bool Variable_is_a(lua_State *L, const types::TypeInfo *ti1, const char* type)
{
        const types::TypeInfo *ti2 = ti_lookup(L, type);
        return ti1 == ti2;
}

/* helper, check if a variable is basic, that is _tolua will succeed */
static bool __Variable_isbasic(lua_State *L, DataSourceBase::shared_ptr &dsb)
{
        const types::TypeInfo *ti = dsb->getTypeInfo();

        if ( Variable_is_a(L, ti, "bool") ||
             Variable_is_a(L, ti, "double") ||
             Variable_is_a(L, ti, "float") ||
             Variable_is_a(L, ti, "uint") ||
             Variable_is_a(L, ti, "int") ||
             Variable_is_a(L, ti, "long") ||
             Variable_is_a(L, ti, "char") ||
             Variable_is_a(L, ti, "uint8") || Variable_is_a(L, ti, "int8") ||
             Variable_is_a(L, ti, "uint16") || Variable_is_a(L, ti, "int16") ||
             Variable_is_a(L, ti, "uint32") || Variable_is_a(L, ti, "int32") ||
             Variable_is_a(L, ti, "uint64") || Variable_is_a(L, ti, "int64") ||
             Variable_is_a(L, ti, "string") ||
             Variable_is_a(L, ti, "void"))
                return true;
        else
                return false;
}

static int Variable_isbasic(lua_State *L)
{
        DataSourceBase::shared_ptr dsb = *(luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr));
        lua_pushboolean(L, __Variable_isbasic(L, dsb));
        return 1;
}


/*
 * converts a DataSourceBase to the corresponding Lua value and pushes
 * that on the stack.
 */
static int __Variable_tolua(lua_State *L, DataSourceBase::shared_ptr dsb)
{
        DataSourceBase *ds = dsb.get();
        const types::TypeInfo* ti = dsb->getTypeInfo();
        assert(ds);

        if(Variable_is_a(L, ti, "bool")) { // bool
                DataSource<bool>* dsb = DataSource<bool>::narrow(ds);
                if(dsb) lua_pushboolean(L, dsb->get());
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "float")) { // float
                DataSource<float>* dsb = DataSource<float>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "double")) { // double
                DataSource<double>* dsb = DataSource<double>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "uint8")) { // uint8_t
                DataSource<uint8_t>* dsb = DataSource<uint8_t>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "int8")) { // int8_t
                DataSource<int8_t>* dsb = DataSource<int8_t>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "uint16")) { // uint16_t
                DataSource<uint16_t>* dsb = DataSource<uint16_t>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "int16")) { // int16_t
                DataSource<int16_t>* dsb = DataSource<int16_t>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "uint32")) { // uint32_t
                DataSource<uint32_t>* dsb = DataSource<uint32_t>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "int32")) { // int32_t
                DataSource<int32_t>* dsb = DataSource<int32_t>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "uint64")) { // uint64_t
                DataSource<uint64_t>* dsb = DataSource<uint64_t>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "int64")) { // int64_t
                DataSource<int64_t>* dsb = DataSource<int64_t>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "uint")) { // uint
                DataSource<unsigned int>* dsb = DataSource<unsigned int>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "long")) { //long
                DataSource<long>* dsb = DataSource<long>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "int")) { // int
                DataSource<int>* dsb = DataSource<int>::narrow(ds);
                if(dsb) lua_pushnumber(L, ((lua_Number) dsb->get()));
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "char")) { // char
                DataSource<char>* dsb = DataSource<char>::narrow(ds);
                char c = dsb->get();
                if(dsb) lua_pushlstring(L, &c, 1);
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "string")) { //string
                DataSource<std::string>* dsb = DataSource<std::string>::narrow(ds);
                if(dsb) lua_pushlstring(L, dsb->get().c_str(), dsb->get().size());
                else goto out_nodsb;
        } else if (Variable_is_a(L, ti, "void")) {
                DataSource<void>* dsb = DataSource<void>::narrow(ds);
                if(dsb) lua_pushnil(L);
                else goto out_nodsb;
        } else {
                goto out_conv_err;
        }

        /* all ok */
        return 1;

 out_conv_err:
        luaL_error(L, "Variable.tolua: can't convert type %s", dsb->getTypeName().c_str());
        return 0;

 out_nodsb:
        luaL_error(L, "Variable.tolua: narrow failed for %s Variable", dsb->getTypeName().c_str());
        return 0;
}

static int Variable_tolua(lua_State *L)
{
        DataSourceBase::shared_ptr dsb = *(luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr));
        return __Variable_tolua(L, dsb);
}

/* Function takes a DSB, that is also expected on the top of the
 * stack. If the DSB is basic, it replaces the dsb with the
 * corresponding Lua value. Otherwise it does nothing, leaving the DSB
 * on the top of the stack.
 */
static void Variable_coerce(lua_State *L, DataSourceBase::shared_ptr dsb)
{
        if (__Variable_isbasic(L, dsb)) {
                lua_pop(L, 1);
                __Variable_tolua(L, dsb);
        }
}

/* this function takes a dsb and either pushes it as a Lua type if the
 * dsb is basic or otherwise as at Variable
 */
static void Variable_push_coerce(lua_State *L, DataSourceBase::shared_ptr dsb)
{
        if (__Variable_isbasic(L, dsb))
                __Variable_tolua(L, dsb);
        else
                luaM_pushobject_mt(L, "Variable", DataSourceBase::shared_ptr)(dsb);

}

static int Variable_getTypes(lua_State *L)
{
        push_vect_str(L, Types()->getTypes());
        return 1;
}

static int Variable_getMemberNames(lua_State *L)
{
        DataSourceBase::shared_ptr *dsbp = luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr);
        push_vect_str(L, (*dsbp)->getMemberNames());
        return 1;
}

static int Variable_tolightuserdata(lua_State *L)
{
        DataSourceBase::shared_ptr dsb = *(luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr));
        lua_pushlightuserdata(L, dsb->getRawPointer());
        return 1;
}


/* caching of DSB members
 * lookup of DSB using getMember and caches result.
 * returns DSB (or nil if lookup fails) on top of stack.
 */
static DataSourceBase::shared_ptr lookup_member(lua_State *L, DataSourceBase::shared_ptr parent, const char* mem)
{
        DataSourceBase *varptr;
        DataSourceBase::shared_ptr *dsbp;
        DataSourceBase::shared_ptr memdsb;
        int top = lua_gettop(L);

        varptr = parent.get();

        lua_pushlightuserdata(L, (void*) varptr);
        lua_rawget(L, LUA_REGISTRYINDEX);

        if(lua_type(L, -1) == LUA_TNIL)
                goto cache_miss;

        lua_pushstring(L, mem);
        lua_rawget(L, -2);

        if ((dsbp = luaM_testudata_mt(L, -1, "Variable", DataSourceBase::shared_ptr)) != NULL) {
                memdsb=*dsbp;
                goto out;
        }

        lua_pop(L, 1); /* pop nil from table lookup */

 cache_miss:
        /* slowpath */
        memdsb = parent->getMember(mem);

        if(memdsb == 0)
                goto out;

        /* if nil is on top of stack, we have to create a new table */
        if(lua_type(L, -1) == LUA_TNIL) {
                lua_newtable(L);                                /* member lookup tab for this Variable */
                lua_pushlightuserdata(L, (void*) varptr); /* index for REGISTRY */
                lua_pushvalue(L, -2);                   /* duplicates table */
                lua_rawset(L, LUA_REGISTRYINDEX);       /* REG[varptr]=newtab */
        }

        /* cache dsb in table */
        lua_pushstring(L, mem);
        luaM_pushobject_mt(L, "Variable", DataSourceBase::shared_ptr)(memdsb);
        lua_rawset(L, -3);                      /* newtab[mem]=memdsb, top is newtab */
        luaM_pushobject_mt(L, "Variable", DataSourceBase::shared_ptr)(memdsb);

 out:
        lua_replace(L, top+1); // make new var top of stack
        lua_settop(L, top+1);

        return memdsb;
}

/* set reg[varptr] to nil so table will be garbage collected */
static void cache_clear(lua_State *L, DataSourceBase *varptr)
{
        lua_pushlightuserdata(L, (void*) varptr);
        lua_pushnil(L);
        lua_rawset(L, LUA_REGISTRYINDEX);
}

static int Variable_getMember(lua_State *L)
{
        DataSourceBase::shared_ptr *dsbp = luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr);
        DataSourceBase::shared_ptr memdsb;
        const char *mem = luaL_checkstring(L, 2);

        if ((memdsb = lookup_member(L, *dsbp, mem)) == 0)
                luaL_error(L, "Variable.getMember: indexing failed, no member %s", mem);
        else
                Variable_coerce(L, memdsb);

        return 1;
}

static int Variable_getMemberRaw(lua_State *L)
{
        DataSourceBase::shared_ptr *dsbp = luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr);
        DataSourceBase::shared_ptr memdsb;
        const char *mem = luaL_checkstring(L, 2);

        if ((memdsb = lookup_member(L, (*dsbp), mem)) == 0)
                luaL_error(L, "Variable.getMemberRaw: indexing failed, no member %s", mem);

        /* else: Variable is already on top of stack */

        return 1;
}

static int Variable_update(lua_State *L)
{
        int ret;
        DataSourceBase::shared_ptr dsb;
        DataSourceBase::shared_ptr *dsbp;
        DataSourceBase::shared_ptr self = *(luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr));

        if ((dsbp = luaM_testudata_mt(L, 2, "Variable", DataSourceBase::shared_ptr)) != NULL) {
                dsb = *dsbp;
                ret = self->update(dsb.get());
                if (!ret) luaL_error(L, "Variable.assign: assignment failed");
        } else {
                Variable_fromlua(L, self, 2);
        }

        return 0;
}

/* create variable */
static int Variable_create(lua_State *L)
{
        const char *type;
        type = luaL_checkstring(L, 1);

        if(!strcmp(type, "void"))
                luaL_error(L, "Variable.new: can't create void variable");

        TypeInfo* ti = Types()->type(type);

        if(ti==0)
                luaL_error(L, "Variable.new: unknown type %s", type);

        luaM_pushobject_mt(L, "Variable", DataSourceBase::shared_ptr)(ti->buildValue());
        return 1;
}

#define CONVERT_TO_NUMBER(CTGT) \
        lua_Number x; \
        if (luatype == LUA_TNUMBER) x = lua_tonumber(L, valind); \
        else goto out_conv_err; \
        AssignableDataSource<CTGT> *ads = ValueDataSource<CTGT>::narrow(dsb.get()); \
        if (ads == NULL) luaL_error(L, "Variable_fromlua: failed to narrow target dsb to %s.", #CTGT ); \
        ads->set((CTGT) x)\

/* Try to convert the Lua value on stack at valind to given DSB
 * if it returns, evertthing is ok */
static void Variable_fromlua(lua_State *L, DataSourceBase::shared_ptr& dsb, int valind)
{
        const types::TypeInfo* ti = dsb->getTypeInfo();

        luaL_checkany(L, valind);
        int luatype = lua_type(L, valind);      /* type of lua variable */

        if(__typenames_cmp(L, ti, "bool")) {
                lua_Number x;
                if(luatype == LUA_TBOOLEAN)
                        x = (lua_Number) lua_toboolean(L, valind);
                else if (luatype == LUA_TNUMBER)
                        x = lua_tonumber(L, valind);
                else
                        goto out_conv_err;

                AssignableDataSource<bool> *ads = ValueDataSource<bool>::narrow(dsb.get());
                if (ads == NULL)
                        luaL_error(L, "Variable_fromlua: failed to narrow target dsb to bool");
                ads->set((bool) x);
        }
        else if (__typenames_cmp(L, ti, "uint"))   { CONVERT_TO_NUMBER(unsigned int); }
        else if (__typenames_cmp(L, ti, "int"))    { CONVERT_TO_NUMBER(int); }
        else if (__typenames_cmp(L, ti, "double")) { CONVERT_TO_NUMBER(double); }
        else if (__typenames_cmp(L, ti, "long"))   { CONVERT_TO_NUMBER(double); }
        else if (__typenames_cmp(L, ti, "uint8"))  { CONVERT_TO_NUMBER(uint8_t); }
        else if (__typenames_cmp(L, ti, "int8"))   { CONVERT_TO_NUMBER(int8_t); }
        else if (__typenames_cmp(L, ti, "uint16")) { CONVERT_TO_NUMBER(uint16_t); }
        else if (__typenames_cmp(L, ti, "int16"))  { CONVERT_TO_NUMBER(int16_t); }
        else if (__typenames_cmp(L, ti, "uint32")) { CONVERT_TO_NUMBER(uint32_t); }
        else if (__typenames_cmp(L, ti, "int32"))  { CONVERT_TO_NUMBER(int32_t); }
        else if (__typenames_cmp(L, ti, "uint64")) { CONVERT_TO_NUMBER(uint64_t); }
        else if (__typenames_cmp(L, ti, "int64"))  { CONVERT_TO_NUMBER(int64_t); }
        else if (__typenames_cmp(L, ti, "float"))  { CONVERT_TO_NUMBER(float); }

        else if (__typenames_cmp(L, ti, "char")) {
                const char *x;
                size_t l;
                if (luatype == LUA_TSTRING) x = lua_tolstring(L, valind, &l);
                else goto out_conv_err;
                AssignableDataSource<char> *ads = ValueDataSource<char>::narrow(dsb.get());
                if (ads == NULL) luaL_error(L, "Variable_fromlua: failed to narrow target dsb to char");
                ads->set((char) x[0]);

        } else if (__typenames_cmp(L, ti, "string")) {
                const char *x;
                if (luatype == LUA_TSTRING) x = lua_tostring(L, valind);
                else goto out_conv_err;
                AssignableDataSource<std::string> *ads = ValueDataSource<std::string>::narrow(dsb.get());
                if (ads == NULL) luaL_error(L, "Variable_fromlua: failed to narrow target dsb to std::string");
                ads->set((std::string) x);

        } else {
                goto out_conv_err;
        }

        /* everybody happy */
        return;

 out_conv_err:
        luaL_error(L, "__lua_todsb: can't convert lua %s to %s variable",
                   lua_typename(L, luatype), ti->getTypeName().c_str());
        return;
}

/* Create a DSB of RTT ti from the Lua value at stack[valind]
 * This one will create a dsb - NRT!*/
static DataSourceBase::shared_ptr Variable_fromlua(lua_State *L, const types::TypeInfo *ti, int valind)
{
        DataSourceBase::shared_ptr dsb = ti->buildValue();
        Variable_fromlua(L, dsb, valind);
        return dsb;
}

/* Create a DSB of RTT type 'type' from the Lua value at stack[valind]
 * This one will create a dsb - NRT!
 * This one should be avoided, to reduce needless name-ti lookups.
 * preferred variant is the one taking TypeInfo * as second arg */
static DataSourceBase::shared_ptr Variable_fromlua(lua_State *L, const char* type, int valind)
{
        const types::TypeInfo* ti = ti_lookup(L, type);
        if(!ti) luaL_error(L, "Variable_fromlua: %s is not a known type. Load typekit?", type);
        return Variable_fromlua(L, ti, valind);
}


static int Variable_create_ival(lua_State *L, int typeind, int valind)
{
        DataSourceBase::shared_ptr dsb;
        luaL_checkany(L, valind);
        const char* type = luaL_checkstring(L, typeind);        /* target dsb type */
        dsb = Variable_fromlua(L, type, valind);
        luaM_pushobject_mt(L, "Variable", DataSourceBase::shared_ptr)(dsb);
        return 1;
}

static int Variable_new(lua_State *L)
{
        int argc = lua_gettop(L);
        if(argc == 1)
                return Variable_create(L);
        else if(argc == 2)
                return Variable_create_ival(L, 1, 2);
        else
                luaL_error(L, "Variable.new: invalid number of args");

        return 0;
}

static int Variable_toString(lua_State *L)
{
        DataSourceBase::shared_ptr *dsbp = luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr);
        lua_pushstring(L, ((*dsbp)->toString()).c_str());
        return 1;
}

static int Variable_getType(lua_State *L)
{
        DataSourceBase::shared_ptr *dsbp = luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr);
        lua_pushstring(L, (*dsbp)->getType().c_str());
        return 1;
}

static int Variable_getTypeIdName(lua_State *L)
{
        DataSourceBase::shared_ptr *dsbp = luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr);
        lua_pushstring(L, (*dsbp)->getTypeInfo()->getTypeIdName());
        return 1;
}

static int Variable_getTypeName(lua_State *L)
{
        DataSourceBase::shared_ptr *dsbp = luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr);
        lua_pushstring(L, (*dsbp)->getTypeName().c_str());
        return 1;
}

static int Variable_resize(lua_State *L)
{
        int size;
        DataSourceBase::shared_ptr *dsbp = luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr);
        size = luaL_checknumber(L, 2);
        const TypeInfo *ti = (*dsbp)->getTypeInfo();
        lua_pushboolean(L, ti->resize(*dsbp, size));
        return 1;
}


/*
 * Operators
 */
static int Variable_unm(lua_State *L)
{
        types::OperatorRepository::shared_ptr opreg = types::OperatorRepository::Instance();
        DataSourceBase::shared_ptr arg = *(luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr));
        DataSourceBase::shared_ptr res = opreg->applyUnary("-", arg.get());
        luaM_pushobject_mt(L, "Variable", DataSourceBase::shared_ptr)(res);
        return 1;
}


/* don't try this at home */
#define gen_opmet(name, op)                                     \
static int name(lua_State *L)                                   \
{                                                               \
        DataSourceBase::shared_ptr arg1 = *(luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr)); \
        DataSourceBase::shared_ptr arg2 = *(luaM_checkudata_mt(L, 2, "Variable", DataSourceBase::shared_ptr)); \
        types::OperatorRepository::shared_ptr opreg = types::OperatorRepository::Instance(); \
        DataSourceBase *res = opreg->applyBinary(#op, arg1.get(), arg2.get()); \
        if(res == 0)                                                    \
                luaL_error(L , "%s (operator %s) failed", #name, #op);  \
        res->evaluate();                                                \
        luaM_pushobject_mt(L, "Variable", DataSourceBase::shared_ptr)(res);     \
        return 1;                                                       \
}                                                                       \

gen_opmet(Variable_add, +)
gen_opmet(Variable_sub, -)
gen_opmet(Variable_mul, *)
gen_opmet(Variable_div, /)
gen_opmet(Variable_mod, %)
gen_opmet(Variable_pow, ^)

/* these flavors convert the boolean return dsb to a lua bool */
#define gen_opmet_bool(name, op)                                \
static int name(lua_State *L)                                   \
{                                                               \
        DataSourceBase::shared_ptr arg1 = *(luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr)); \
        DataSourceBase::shared_ptr arg2 = *(luaM_checkudata_mt(L, 2, "Variable", DataSourceBase::shared_ptr)); \
        types::OperatorRepository::shared_ptr opreg = types::OperatorRepository::Instance(); \
        DataSourceBase *res = opreg->applyBinary(#op, arg1.get(), arg2.get()); \
        if(res == 0)                                                    \
                luaL_error(L , "%s (operator %s) failed", #name, #op);  \
        res->evaluate();                                                \
        return __Variable_tolua(L, res);                                \
}                                                                       \

gen_opmet_bool(Variable_eq, ==)
gen_opmet_bool(Variable_lt, <)
gen_opmet_bool(Variable_le, <=)

static int Variable_opBinary(lua_State *L)
{
        types::OperatorRepository::shared_ptr opreg = types::OperatorRepository::Instance();
        const char *op = luaL_checkstring(L, 1);
        DataSourceBase::shared_ptr arg1 = *(luaM_checkudata_mt(L, 2, "Variable", DataSourceBase::shared_ptr));
        DataSourceBase::shared_ptr arg2 = *(luaM_checkudata_mt(L, 3, "Variable", DataSourceBase::shared_ptr));
        DataSourceBase *res;

        res = opreg->applyBinary(op, arg1.get(), arg2.get());
        if(res == 0)
                luaL_error(L , "Variable.opBinary '%s' not applicable to args", op);

        res->evaluate();

        luaM_pushobject_mt(L, "Variable", DataSourceBase::shared_ptr)(res);
        return 1;
}

/*
 * this is a dispatcher which checks if the key is a method, otherwise
 * calls get for looking up the field. Inspired by
 * http://lua-users.org/wiki/ObjectProperties
 */
static int Variable_index(lua_State *L)
{
        const char* key = luaL_checkstring(L, 2);

        lua_getmetatable(L, 1);
        lua_getfield(L, -1, key);

        /* Either key is name of a method in the metatable */
        if(!lua_isnil(L, -1))
                return 1;

        /* ... or its a field access, so recall as self.get(self, value). */
        lua_settop(L, 2);
        return Variable_getMember(L);
}

static int Variable_newindex(lua_State *L)
{
        DataSourceBase::shared_ptr *newvalp;
        DataSourceBase::shared_ptr newval;
        DataSourceBase::shared_ptr parent = *(luaM_checkudata_mt(L, 1, "Variable", DataSourceBase::shared_ptr));
        const char* mem = luaL_checkstring(L, 2);

        /* get dsb to be updated: we need its type before get-or-create'ing arg3 */
        types::OperatorRepository::shared_ptr opreg = types::OperatorRepository::Instance();
        DataSourceBase::shared_ptr curval;

        if ((curval = lookup_member(L, parent, mem)) == 0)
                luaL_error(L, "Variable.newindex: indexing failed, no member %s", mem);


        /* assigning a DSB */
        if ((newvalp = luaM_testudata_mt(L, 3, "Variable", DataSourceBase::shared_ptr)) != NULL) {
                newval = *newvalp;
                if(!curval->update(newval.get())) {
                        luaL_error(L, "Variable.newindex: failed to assign %s to member %s of type %s",
                                   newval->getType().c_str(), mem, curval->getType().c_str());
                }
        } else /* assigning basic type */
                Variable_fromlua(L, curval, 3);
        return 1;
}

// Why doesn't the following work:
// static int Variable_gc(lua_State *L)
// {
//      DataSourceBase::shared_ptr *dsbp = (DataSourceBase::shared_ptr*) lua_touserdata(L, 1);
//      cache_clear(L, dsbp->get());
//      dsbp->~DataSourceBase::shared_ptr();
//      return 0;
// }

template<typename T>
int VariableGC(lua_State* L)
{
        T* dsbp = (T*) lua_touserdata(L, 1);
        cache_clear(L, dsbp->get());
        reinterpret_cast<T*>(dsbp)->~T();
        return 0;
}


static const struct luaL_Reg Variable_f [] = {
        { "new", Variable_new },
        { "tolua", Variable_tolua },
        { "isbasic", Variable_isbasic },
        { "toString", Variable_toString },
        { "getTypes", Variable_getTypes },
        { "getType", Variable_getType },
        { "getTypeName", Variable_getTypeName },
        { "getTypeIdName", Variable_getTypeIdName },
        { "getMemberNames", Variable_getMemberNames },
        { "getMember", Variable_getMember },
        { "getMemberRaw", Variable_getMemberRaw },
        { "tolud", Variable_tolightuserdata },
        { "resize", Variable_resize },
        { "opBinary", Variable_opBinary },
        { "assign", Variable_update }, /* assign seems a better name than update */
        { "unm", Variable_unm },
        { "add", Variable_add },
        { "sub", Variable_sub },
        { "mul", Variable_mul },
        { "div", Variable_div },
        { "mod", Variable_mod },
        { "pow", Variable_pow },
        { "eq", Variable_eq },
        { "lt", Variable_lt },
        { "le", Variable_le },
        { NULL, NULL}
};

static const struct luaL_Reg Variable_m [] = {
        { "tolua", Variable_tolua },
        { "isbasic", Variable_isbasic },
        { "toString", Variable_toString },
        { "getType", Variable_getType },
        { "getTypeName", Variable_getTypeName },
        { "getTypeIdName", Variable_getTypeIdName },
        { "getMemberNames", Variable_getMemberNames },
        { "getMember", Variable_getMember },
        { "getMemberRaw", Variable_getMemberRaw },
        { "tolud", Variable_tolightuserdata },
        { "resize", Variable_resize },
        { "opBinary", Variable_opBinary },
        { "assign", Variable_update }, /* assign seems a better name than update */
        { "__unm", Variable_unm },
        { "__add", Variable_add },
        { "__sub", Variable_sub },
        { "__mul", Variable_mul },
        { "__div", Variable_div },
        { "__mod", Variable_mod },
        { "__pow", Variable_pow },
        { "__eq", Variable_eq },
        { "__lt", Variable_lt },
        { "__le", Variable_le },
        { "__index", Variable_index },
        { "__newindex", Variable_newindex },
        // { "__gc", GCMethod<DataSourceBase::shared_ptr> },
        // {"__gc", Variable_gc},
        {"__gc", VariableGC<DataSourceBase::shared_ptr> },
        { NULL, NULL}
};


/***************************************************************
 * Property (boxed)
 ***************************************************************/

gen_push_bxptr(Property_push, "Property", PropertyBase)

static int Property_new(lua_State *L)
{
        const char *type, *name, *desc;
        PropertyBase *pb;
        int argc = lua_gettop(L);
        type = luaL_checkstring(L, 1);

        /* name and description are optional */
        name = (argc > 1) ? luaL_checkstring(L, 2) : "";
        desc = (argc > 2) ? luaL_checkstring(L, 3) : "";

        types::TypeInfo *ti = types::TypeInfoRepository::Instance()->type(type);

        if(!ti)
                luaL_error(L, "Property.new: unknown type %s", type);

        pb =  ti->buildProperty(name, desc);
        Property_push(L, pb);
        return 1;
}

static int Property_get(lua_State *L)
{
        PropertyBase *pb = *(luaM_checkudata_mt_bx(L, 1, "Property", PropertyBase));
        Variable_push_coerce(L, pb->getDataSource());
        return 1;
}

static int Property_getRaw(lua_State *L)
{
        PropertyBase *pb = *(luaM_checkudata_mt_bx(L, 1, "Property", PropertyBase));
        luaM_pushobject_mt(L, "Variable", DataSourceBase::shared_ptr)(pb->getDataSource());
        return 1;
}

static int Property_set(lua_State *L)
{
        DataSourceBase::shared_ptr newdsb;
        DataSourceBase::shared_ptr *newdsbp;
        DataSourceBase::shared_ptr propdsb;
        PropertyBase *pb = *(luaM_checkudata_mt_bx(L, 1, "Property", PropertyBase));
        propdsb = pb->getDataSource();

        /* assigning a DSB */
        if ((newdsbp = luaM_testudata_mt(L, 2, "Variable", DataSourceBase::shared_ptr)) != NULL) {
                newdsb = *newdsbp;
                if(!propdsb->update(newdsb.get()))
                        luaL_error(L, "Property.set: failed to assign type %s to type %s",
                                   newdsb->getType().c_str(), propdsb->getType().c_str());
        } else { /* assigning a Lua value */
                Variable_fromlua(L, propdsb, 2);
        }
        return 1;
}

static int Property_info(lua_State *L)
{
        PropertyBase *pb = *(luaM_checkudata_mt_bx(L, 1, "Property", PropertyBase));
        lua_newtable(L);
        lua_pushstring(L, "name"); lua_pushstring(L, pb->getName().c_str()); lua_rawset(L, -3);
        lua_pushstring(L, "desc"); lua_pushstring(L, pb->getDescription().c_str()); lua_rawset(L, -3);
        lua_pushstring(L, "type"); lua_pushstring(L, pb->getType().c_str()); lua_rawset(L, -3);
        return 1;
}

#if NOT_USED_YET
/*
 * Race condition if we collect properties: if we add this property to
 * a TC and our life ends before that of the TC, the property will be
 * deleted before the TaskContext.
 */
static int Property_gc(lua_State *L)
{
        PropertyBase *pb = *(luaM_checkudata_mt_bx(L, 1, "Property", PropertyBase));
        delete pb;
        return 0;
}
#endif

/* only explicit destruction allowed */
static int Property_del(lua_State *L)
{
        PropertyBase *pb = *(luaM_checkudata_mt_bx(L, 1, "Property", PropertyBase));
        delete pb;

        /* this prevents calling rtt methods which would cause a crash */
        luaL_getmetatable(L, "__dead__");
        lua_setmetatable(L, -2);
        return 0;
}

/* indexability of properties */
/*
 * this is a dispatcher which checks if the key is a method, otherwise
 * calls get for looking up the field. Inspired by
 * http://lua-users.org/wiki/ObjectProperties
 */
static int Property_index(lua_State *L)
{
        const char* key = luaL_checkstring(L, 2);

        lua_getmetatable(L, 1);
        lua_getfield(L, -1, key); /* this actually calls the method */

        /* Either key is name of a method in the metatable */
        if(!lua_isnil(L, -1))
                return 1;

        lua_settop(L, 2);       /* reset stack */
        Property_get(L);        /* pushes property var */
        lua_replace(L, 1);      /* replace prop with var */
        return Variable_index(L);
}

static int Property_newindex(lua_State *L)
{
        Property_get(L);
        lua_replace(L, 1);
        return Variable_newindex(L);
}

static const struct luaL_Reg Property_f [] = {
        {"new", Property_new },
        {"get", Property_get },
        {"getRaw", Property_getRaw },
        {"set", Property_set },
        {"info", Property_info },
        {"delete", Property_del },
        {NULL, NULL}
};

static const struct luaL_Reg Property_m [] = {
        {"get", Property_get },
        {"getRaw", Property_getRaw },
        {"set", Property_set },
        {"info", Property_info },
        // todo: shall we or not? s.o. {"__gc", Property_gc },
        {"delete", Property_del },
        {"__index", Property_index },
        {"__newindex", Property_newindex },
        {NULL, NULL}
};

/***************************************************************
 * Attribute (boxed)
 ***************************************************************/

gen_push_bxptr(Attribute_push, "Attribute", AttributeBase)

static int Attribute_new(lua_State *L)
{
        const char *type, *name;
        AttributeBase *pb;
        int argc = lua_gettop(L);
        type = luaL_checkstring(L, 1);

        /* name and description are optional */
        name = (argc > 1) ? luaL_checkstring(L, 2) : "";

        types::TypeInfo *ti = types::TypeInfoRepository::Instance()->type(type);

        if(!ti)
                luaL_error(L, "Attribute.new: unknown type %s", type);

        pb =  ti->buildAttribute(name);
        Attribute_push(L, pb);
        return 1;
}

static int Attribute_get(lua_State *L)
{
        AttributeBase *pb = *(luaM_checkudata_mt_bx(L, 1, "Attribute", AttributeBase));
        Variable_push_coerce(L, pb->getDataSource());
        return 1;
}

static int Attribute_getRaw(lua_State *L)
{
        AttributeBase *pb = *(luaM_checkudata_mt_bx(L, 1, "Attribute", AttributeBase));
        luaM_pushobject_mt(L, "Variable", DataSourceBase::shared_ptr)(pb->getDataSource());
        return 1;
}

static int Attribute_set(lua_State *L)
{
        DataSourceBase::shared_ptr newdsb;
        DataSourceBase::shared_ptr *newdsbp;
        DataSourceBase::shared_ptr propdsb;
        AttributeBase *pb = *(luaM_checkudata_mt_bx(L, 1, "Attribute", AttributeBase));
        propdsb = pb->getDataSource();

        /* assigning a DSB */
        if ((newdsbp = luaM_testudata_mt(L, 2, "Variable", DataSourceBase::shared_ptr)) != NULL) {
                newdsb = *newdsbp;
                if(!propdsb->update(newdsb.get()))
                        luaL_error(L, "Attribute.set: failed to assign type %s to type %s",
                                   newdsb->getType().c_str(), propdsb->getType().c_str());
        } else { /* assigning a Lua value */
                Variable_fromlua(L, propdsb, 2);
        }
        return 1;
}

static int Attribute_info(lua_State *L)
{
        AttributeBase *pb = *(luaM_checkudata_mt_bx(L, 1, "Attribute", AttributeBase));
        lua_newtable(L);
        lua_pushstring(L, "name"); lua_pushstring(L, pb->getName().c_str()); lua_rawset(L, -3);
        lua_pushstring(L, "type"); lua_pushstring(L, pb->getDataSource()->getType().c_str()); lua_rawset(L, -3);
        return 1;
}

#if NOT_USED_YET
/*
 * Race condition if we collect properties: if we add this attribute to
 * a TC and our life ends before that of the TC, the attribute will be
 * deleted before the TaskContext.
 */
static int Attribute_gc(lua_State *L)
{
        AttributeBase *pb = *(luaM_checkudata_mt_bx(L, 1, "Attribute", AttributeBase));
        delete pb;
        return 0;
}
#endif


/* only explicit destruction allowed */
static int Attribute_del(lua_State *L)
{
        AttributeBase *pb = *(luaM_checkudata_mt_bx(L, 1, "Attribute", AttributeBase));
        delete pb;

        /* this prevents calling rtt methods which would cause a crash */
        luaL_getmetatable(L, "__dead__");
        lua_setmetatable(L, -2);
        return 0;
}

/* indexability of properties */
/*
 * this is a dispatcher which checks if the key is a method, otherwise
 * calls get for looking up the field. Inspired by
 * http://lua-users.org/wiki/ObjectProperties
 */
static int Attribute_index(lua_State *L)
{
        const char* key = luaL_checkstring(L, 2);

        lua_getmetatable(L, 1);
        lua_getfield(L, -1, key); /* this actually calls the method */

        /* Either key is name of a method in the metatable */
        if(!lua_isnil(L, -1))
                return 1;

        lua_settop(L, 2);       /* reset stack */
        Attribute_get(L);       /* pushes attribute var */
        lua_replace(L, 1);      /* replace prop with var */
        return Variable_index(L);
}

static int Attribute_newindex(lua_State *L)
{
        Attribute_get(L);
        lua_replace(L, 1);
        return Variable_newindex(L);
}

static const struct luaL_Reg Attribute_f [] = {
        {"new", Attribute_new },
        {"get", Attribute_get },
        {"getRaw", Attribute_getRaw },
        {"set", Attribute_set },
        {"info", Attribute_info },
        {"delete", Attribute_del },
        {NULL, NULL}
};

static const struct luaL_Reg Attribute_m [] = {
        {"get", Attribute_get },
        {"getRaw", Attribute_getRaw },
        {"set", Attribute_set },
        {"info", Attribute_info },
        // todo: shall we or not? s.o. {"__gc", Attribute_gc },
        {"delete", Attribute_del },
        {"__index", Attribute_index },
        {"__newindex", Attribute_newindex },
        {NULL, NULL}
};

/***************************************************************
 * Ports (boxed)
 ***************************************************************/

/* both input or output */
static int Port_info(lua_State *L)
{
        int arg_type;
        const char* port_type = NULL;
        PortInterface **pip;
        PortInterface *pi = NULL;

        if((pip = (PortInterface**) luaL_testudata(L, 1, "InputPort")) != NULL) {
                pi = *pip;
                port_type = "in";
        } else if((pip = (PortInterface**) luaL_testudata(L, 1, "OutputPort")) != NULL) {
                pi = *pip;
                port_type = "out";
        }
        else {
                arg_type = lua_type(L, 1);
                luaL_error(L, "Port.info: invalid argument, expected Port, got %s",
                           lua_typename(L, arg_type));
        }

        lua_newtable(L);
        lua_pushstring(L, "name"); lua_pushstring(L, pi->getName().c_str()); lua_rawset(L, -3);
        lua_pushstring(L, "desc"); lua_pushstring(L, pi->getDescription().c_str()); lua_rawset(L, -3);
        lua_pushstring(L, "connected"); lua_pushboolean(L, pi->connected()); lua_rawset(L, -3);
        lua_pushstring(L, "isLocal"); lua_pushboolean(L, pi->isLocal()); lua_rawset(L, -3);
        lua_pushstring(L, "type"); lua_pushstring(L, pi->getTypeInfo()->getTypeName().c_str()); lua_rawset(L, -3);
        lua_pushstring(L, "porttype"); lua_pushstring(L, port_type); lua_rawset(L, -3);

        return 1;
}

static int Port_connect(lua_State *L)
{
        int arg_type, ret;
        PortInterface **pip1, **pip2;
        PortInterface *pi1 = NULL;
        PortInterface *pi2 = NULL;
        ConnPolicy **cpp;
        ConnPolicy *cp = NULL;

        if((pip1 = (PortInterface**) luaL_testudata(L, 1, "InputPort")) != NULL) {
                pi1= *pip1;
        } else if((pip1 = (PortInterface**) luaL_testudata(L, 1, "OutputPort")) != NULL) {
                pi1= *pip1;
        }
        else {
                arg_type = lua_type(L, 1);
                luaL_error(L, "Port.info: invalid argument 1, expected Port, got %s",
                           lua_typename(L, arg_type));
        }
        if((pip2 = (PortInterface**) luaL_testudata(L, 2, "InputPort")) != NULL) {
                pi2= *pip2;
        } else if((pip2 = (PortInterface**) luaL_testudata(L, 2, "OutputPort")) != NULL) {
                pi2= *pip2;
        }
        else {
                arg_type = lua_type(L, 2);
                luaL_error(L, "Port.connect: invalid argument 2, expected Port, got %s",
                           lua_typename(L, arg_type));
        }

        if((cpp = (ConnPolicy**) luaL_testudata(L, 3, "ConnPolicy")) != NULL) {
                cp=*cpp;
        }

        if ( cp )
                ret = pi1->connectTo(pi2, *cp);
        else
                ret = pi1->connectTo(pi2);

        lua_pushboolean(L, ret);

        return 1;
}

static int Port_disconnect(lua_State *L)
{
        int arg_type, ret;
        PortInterface **pip1, **pip2;
        PortInterface *pi1 = NULL;
        PortInterface *pi2 = NULL;

        if((pip1 = (PortInterface**) luaL_testudata(L, 1, "InputPort")) != NULL) {
                pi1= *pip1;
        } else if((pip1 = (PortInterface**) luaL_testudata(L, 1, "OutputPort")) != NULL) {
                pi1= *pip1;
        }
        else {
                arg_type = lua_type(L, 1);
                luaL_error(L, "Port.info: invalid argument 1, expected Port, got %s",
                        lua_typename(L, arg_type));
        }
        if((pip2 = (PortInterface**) luaL_testudata(L, 2, "InputPort")) != NULL) {
                pi2= *pip2;
        } else if((pip2 = (PortInterface**) luaL_testudata(L, 2, "OutputPort")) != NULL) {
                pi2= *pip2;
        }

        if (pi2 != NULL)
                ret = pi1->disconnect(pi2);
        else{
                pi1->disconnect();
                ret = 1;
        }
        lua_pushboolean(L, ret);

        return 1;
}



/* InputPort (boxed) */

gen_push_bxptr(InputPort_push, "InputPort", InputPortInterface)

static int InputPort_new(lua_State *L)
{
        const char *type, *name, *desc;
        InputPortInterface* ipi;
        int argc = lua_gettop(L);

        type = luaL_checkstring(L, 1);

        /* name and description are optional */
        name = (argc > 1) ? luaL_checkstring(L, 2) : "";
        desc = (argc > 2) ? luaL_checkstring(L, 3) : "";

        types::TypeInfo *ti = types::TypeInfoRepository::Instance()->type(type);
        if(ti==0)
                luaL_error(L, "InputPort.new: unknown type %s", type);

        ipi = ti->inputPort(name);

        if(!ipi)
                luaL_error(L, "InputPort.new: creating port of type %s failed", type);

        ipi->doc(desc);
        InputPort_push(L, ipi);
        return 1;
}

static int InputPort_read(lua_State *L)
{
        int ret = 1;
        InputPortInterface *ip = *(luaM_checkudata_mt_bx(L, 1, "InputPort", InputPortInterface));
        DataSourceBase::shared_ptr dsb;
        DataSourceBase::shared_ptr *dsbp;
        FlowStatus fs;

        /* if we get don't get a DS to store the result, create one */
        if ((dsbp = luaM_testudata_mt(L, 2, "Variable", DataSourceBase::shared_ptr)) != NULL)
                dsb = *dsbp;
        else {
                dsb = ip->getTypeInfo()->buildValue();
                ret = 2;
        }

        fs = ip->read(dsb);

        if(fs == NoData) lua_pushstring(L, "NoData");
        else if (fs == NewData) lua_pushstring(L, "NewData");
        else if (fs == OldData) lua_pushstring(L, "OldData");
        else luaL_error(L, "InputPort.read: unknown FlowStatus returned");

        if(ret>1)
                Variable_push_coerce(L, dsb);

        return ret;
}

#ifdef NOT_USED_YET
static int InputPort_gc(lua_State *L)
{
        InputPortInterface *ip = *(luaM_checkudata_mt_bx(L, 1, "InputPort", InputPortInterface));
        delete ip;
        return 0;
}
#endif

/* only explicit destruction allowed */
static int InputPort_del(lua_State *L)
{
        InputPortInterface *ip = *(luaM_checkudata_mt_bx(L, 1, "InputPort", InputPortInterface));
        delete ip;

        /* this prevents calling rtt methods which would cause a crash */
        luaL_getmetatable(L, "__dead__");
        lua_setmetatable(L, -2);
        return 0;
}

static const struct luaL_Reg InputPort_f [] = {
        {"new", InputPort_new },
        {"read", InputPort_read },
        {"info", Port_info },
        {"connect", Port_connect },
        {"disconnect", Port_disconnect },
        {"delete", InputPort_del },
        {NULL, NULL}
};

static const struct luaL_Reg InputPort_m [] = {
        {"read", InputPort_read },
        {"info", Port_info },
        {"delete", InputPort_del },
        {"connect", Port_connect },
        {"disconnect", Port_disconnect },
        /* {"__gc", InputPort_gc }, */
        {NULL, NULL}
};

/* OutputPort */

gen_push_bxptr(OutputPort_push, "OutputPort", OutputPortInterface)


static int OutputPort_new(lua_State *L)
{
        const char *type, *name, *desc;
        OutputPortInterface* opi;
        int argc = lua_gettop(L);

        type = luaL_checkstring(L, 1);

        /* name and description are optional */
        name = (argc > 1) ? luaL_checkstring(L, 2) : "";
        desc = (argc > 2) ? luaL_checkstring(L, 3) : "";

        types::TypeInfo *ti = types::TypeInfoRepository::Instance()->type(type);

        if(ti==0)
                luaL_error(L, "OutputPort.new: unknown type %s", type);

        opi = ti->outputPort(name);

        if(!opi)
                luaL_error(L, "OutputPort.new: creating port of type %s failed", type);

        opi->doc(desc);
        OutputPort_push(L, opi);
        return 1;
}

static int OutputPort_write(lua_State *L)
{
        DataSourceBase::shared_ptr dsb;
        DataSourceBase::shared_ptr *dsbp;

        OutputPortInterface *op = *(luaM_checkudata_mt_bx(L, 1, "OutputPort", OutputPortInterface));

        /* fastpath: Variable argument */
        if ((dsbp = luaM_testudata_mt(L, 2, "Variable", DataSourceBase::shared_ptr)) != NULL) {
                dsb = *dsbp;
        } else  {
                /* slowpath: convert lua value to dsb */
                dsb = Variable_fromlua(L, op->getTypeInfo(), 2);
        }
        op->write(dsb);
        return 0;
}

#ifdef NOT_USED_YET
static int OutputPort_gc(lua_State *L)
{
        OutputPortInterface *op = *(luaM_checkudata_mt_bx(L, 1, "OutputPort", OutputPortInterface));
        delete op;
        return 0;
}
#endif

/* only explicit destruction allowed */
static int OutputPort_del(lua_State *L)
{
        OutputPortInterface *op = *(luaM_checkudata_mt_bx(L, 1, "OutputPort", OutputPortInterface));
        delete op;

        /* this prevents calling rtt methods which would cause a crash */
        luaL_getmetatable(L, "__dead__");
        lua_setmetatable(L, -2);
        return 0;
}

static const struct luaL_Reg OutputPort_f [] = {
        {"new", OutputPort_new },
        {"write", OutputPort_write },
        {"info", Port_info },
        {"connect", Port_connect },
        {"disconnect", Port_disconnect },
        {"delete", OutputPort_del },
        {NULL, NULL}
};

static const struct luaL_Reg OutputPort_m [] = {
        {"write", OutputPort_write },
        {"info", Port_info },
        {"connect", Port_connect },
        {"disconnect", Port_disconnect },
        {"delete", OutputPort_del },
        /* {"__gc", OutputPort_gc }, */
        {NULL, NULL}
};

/***************************************************************
 * Operation
 ***************************************************************/

struct OperationHandle {
        OperationInterfacePart *oip;
        OperationCallerC *occ;
        unsigned int arity;
        bool is_void;

        /* we need to store references to the dsb which we created
           on-the-fly, because the ReferenceDSB does not hold a
           shared_ptr, and hence these DSN might get destructed
           before/during the call
         */
        std::vector<base::DataSourceBase::shared_ptr> dsb_store;
        std::vector<internal::Reference*> args;
        base::DataSourceBase::shared_ptr call_dsb;
        base::DataSourceBase::shared_ptr ret_dsb;
};

template<typename T>
int OperationGC(lua_State* L)
{
        T* oh = (T*) lua_touserdata(L, 1);
        delete oh->occ;
        reinterpret_cast<T*>(lua_touserdata(L, 1))->~T();
        return 0;
}

static int Operation_info(lua_State *L)
{
        int i=1;
        std::vector<ArgumentDescription> args;
        OperationHandle *op = luaM_checkudata_mt(L, 1, "Operation", OperationHandle);

        lua_pushstring(L, op->oip->getName().c_str());          /* name */
        lua_pushstring(L, op->oip->description().c_str());      /* description */
        lua_pushstring(L, op->oip->resultType().c_str());       /* result type */
        lua_pushinteger(L, op->arity);                          /* arity */

        args = op->oip->getArgumentList();

        lua_newtable(L);

        for (std::vector<ArgumentDescription>::iterator it = args.begin(); it != args.end(); it++) {
                lua_newtable(L);
                lua_pushstring(L, "name"); lua_pushstring(L, it->name.c_str()); lua_rawset(L, -3);
                lua_pushstring(L, "type"); lua_pushstring(L, it->type.c_str()); lua_rawset(L, -3);
                lua_pushstring(L, "desc"); lua_pushstring(L, it->description.c_str()); lua_rawset(L, -3);
                lua_rawseti(L, -2, i++);
        }
        return 5;
}

static int __Operation_call(lua_State *L)
{
        bool ret;
        DataSourceBase::shared_ptr dsb, *dsbp;

        OperationHandle *oh = luaM_checkudata_mt(L, 1, "Operation", OperationHandle);
        OperationInterfacePart *oip = oh->oip;
        unsigned int argc = lua_gettop(L);

        if(oh->arity != argc-1)
                luaL_error(L, "Operation.call: wrong number of args. expected %d, got %d", oh->arity, argc-1);

        /* update dsbs */
        for(unsigned int arg=2; arg<=argc; arg++) {
                /* fastpath: Variable argument */
                if ((dsbp = luaM_testudata_mt(L, arg, "Variable", DataSourceBase::shared_ptr)) != NULL) {
                        dsb = *dsbp;
                } else {
                        /* slowpath: convert lua value to dsb */
                        dsb = Variable_fromlua(L, oip->getArgumentType(arg-1), arg);
                        /* this dsb must outlive occ->call (see comment in
                           OperationHandle def.): */
                        oh->dsb_store.push_back(dsb);
                }
                if(!dsb->isAssignable())
                        luaL_error(L, "Operation.call: argument %d is not assignable.", arg-1);

                ret = oh->args[arg-2]->setReference(dsb);
                if (!ret)
                        luaL_error(L, "Operation_call: setReference failed, wrong type of argument?");
        }

        if(!oh->occ->call())
                luaL_error(L, "Operation.call: call failed.");

        oh->dsb_store.clear();

        if(!oh->is_void)
                Variable_push_coerce(L, oh->ret_dsb);
        else
                lua_pushnil(L);
        return 1;
}

static int __Operation_send(lua_State *L)
{
        DataSourceBase::shared_ptr dsb, *dsbp;

        OperationHandle *oh = luaM_checkudata_mt(L, 1, "Operation", OperationHandle);
        OperationInterfacePart *oip = oh->oip;
        unsigned int argc = lua_gettop(L);

        if(oh->arity != argc-1)
                luaL_error(L, "Operation.send: wrong number of args. expected %d, got %d", oh->arity, argc-1);

        /* update dsbs */
        for(unsigned int arg=2; arg<=argc; arg++) {
                /* fastpath: Variable argument */
                if ((dsbp = luaM_testudata_mt(L, arg, "Variable", DataSourceBase::shared_ptr)) != NULL) {
                        dsb = *dsbp;
                } else {
                        /* slowpath: convert lua value to dsb */
                        dsb = Variable_fromlua(L, oip->getArgumentType(arg-1), arg);
                        /* this dsb must outlive occ->call (see comment in
                           OperationHandle def.): */
                        oh->dsb_store.push_back(dsb);
                }
                oh->args[arg-2]->setReference(dsb);
        }

        luaM_pushobject_mt(L, "SendHandle", SendHandleC)(oh->occ->send());
        return 1;
}

static int Operation_call(lua_State *L)
{
        int ret;
        try {
                ret = __Operation_call(L);
        } catch(const std::exception &exc) {
                luaL_error(L, "Operation.call: caught exception '%s'", exc.what());
        } catch(...) {
                luaL_error(L, "Operation.call: caught unknown exception");
        }
        return ret;
}

static int Operation_send(lua_State *L)
{
        int ret;
        try {
                ret = __Operation_send(L);
        } catch(const std::exception &exc) {
                luaL_error(L, "Operation.send: caught exception '%s'", exc.what());
        } catch(...) {
                luaL_error(L, "Operation.send: caught unknown exception");
        }
        return ret;
}


static const struct luaL_Reg Operation_f [] = {
        { "info", Operation_info },
        { "call", Operation_call },
        { "send", Operation_send },
        { NULL, NULL }

};

static const struct luaL_Reg Operation_m [] = {
        { "info", Operation_info },
        { "send", Operation_send },
        { "__call", Operation_call },
        { "__gc", OperationGC<OperationHandle> },
        { NULL, NULL }
};

/***************************************************************
 * Service (boxed)
 ***************************************************************/

static int Service_getName(lua_State *L)
{
        Service::shared_ptr srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        lua_pushstring(L, srv->getName().c_str());
        return 1;
}

static int Service_doc(lua_State *L)
{
        int ret;
        const char* doc;
        Service::shared_ptr srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        if(lua_gettop(L) == 1) {
                lua_pushstring(L, srv->doc().c_str());
                ret = 1;
        } else {
                doc = luaL_checkstring(L, 2);
                srv->doc(doc);
                ret = 0;
        }

        return ret;
}

static int Service_getProviderNames(lua_State *L)
{
        Service::shared_ptr srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        push_vect_str(L, srv->getProviderNames());
        return 1;
}

static int Service_getOperationNames(lua_State *L)
{
        Service::shared_ptr srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        push_vect_str(L, srv->getOperationNames());
        return 1;
}


static int Service_hasOperation(lua_State *L)
{
        int ret;
        Service::shared_ptr srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        const char* op = luaL_checkstring(L, 2);
        ret = srv->hasOperation(op);
        lua_pushboolean(L, ret);
        return 1;
}

static int Service_getPortNames(lua_State *L)
{
        Service::shared_ptr srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        push_vect_str(L, srv->getPortNames());
        return 1;
}

static int Service_provides(lua_State *L)
{
        int ret, i, argc;
        const char* subsrv_str;
        Service::shared_ptr srv, subsrv;

        srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        argc=lua_gettop(L);

        /* return "this" if no args given */
        if(argc == 1) {
                ret = 1;
                goto out;
        }

        for(i=2; i<=argc; i++) {
                subsrv_str = luaL_checkstring(L, i);
                subsrv = srv->getService(subsrv_str);
                if (subsrv == 0)
                        luaL_error(L, "Service.provides: no subservice %s of service %s",
                                subsrv_str, srv->getName().c_str() );
                else
                        luaM_pushobject_mt(L, "Service", Service::shared_ptr)(subsrv);
        }
        ret = argc - 1;

 out:
        return ret;
}

/* returns restype, arity, table-of-arg-descr */
static int Service_getOperationInfo(lua_State *L)
{
        int i=1;
        Service *serv = *(luaM_checkudata_bx(L, 1, Service));
        const char *op = luaL_checkstring(L, 2);
        std::vector<ArgumentDescription> args;

        if(!serv->hasMember(op))
                luaL_error(L, "Service.getOperationInfo failed: no such operation");

        lua_pushstring(L, serv->getDescription(op).c_str()); /* description */
        lua_pushstring(L, serv->getResultType(op).c_str()); /* result type */
        lua_pushinteger(L, serv->getArity(op));         /* arity */

        args = serv->getArgumentList(op);

        lua_newtable(L);

        for (std::vector<ArgumentDescription>::iterator it = args.begin(); it != args.end(); it++) {
                lua_newtable(L);
                lua_pushstring(L, "name"); lua_pushstring(L, it->name.c_str()); lua_rawset(L, -3);
                lua_pushstring(L, "type"); lua_pushstring(L, it->type.c_str()); lua_rawset(L, -3);
                lua_pushstring(L, "desc"); lua_pushstring(L, it->description.c_str()); lua_rawset(L, -3);
                lua_rawseti(L, -2, i++);
        }

        return 4;
}

static int Service_getOperation(lua_State *L)
{
        const char *op_str;
        OperationInterfacePart *oip;
        Service::shared_ptr srv;
        DataSourceBase::shared_ptr dsb;
        const types::TypeInfo *ti;
        OperationHandle *oh;
        TaskContext *this_tc;

        srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        op_str = luaL_checkstring(L, 2);
        oip = srv->getOperation(op_str);

        if(!oip)
                luaL_error(L, "Service_getOperation: service %s has no operation %s",
                           srv->getName().c_str(), op_str);

        oh = (OperationHandle*) luaM_pushobject_mt(L, "Operation", OperationHandle)();
        oh->oip = oip;
        oh->arity = oip->arity();
        oh->args.reserve(oh->arity);
        this_tc = __getTC(L);

        oh->occ = new OperationCallerC(oip, op_str, this_tc->engine());

        /* create args
         * getArgumentType(0) is return value
         */
        for(unsigned int arg=1; arg <= oh->arity; arg++) {
                std::string type = oip->getArgumentType(arg)->getTypeName();
                ti = types::TypeInfoRepository::Instance()->type(type);
                if(!ti)
                        luaL_error(L, "Operation.call: '%s', failed to locate TypeInfo for arg %d of type '%s'",
                                   op_str, arg, type.c_str());

                dsb = ti->buildReference((void*) 0xdeadbeef);
                if(!dsb)
                        luaL_error(L, "Operation.call: '%s', failed to build DSB for arg %d of type '%s'",
                                   op_str, arg, type.c_str());

                oh->args.push_back(dynamic_cast<internal::Reference*>(dsb.get()));
                oh->occ->arg(dsb);
        }

        /* return value */
        if(oip->resultType() != "void"){
                ti = oip->getArgumentType(0); // 0 == return type
                if(!ti)
                        luaL_error(L, "Operation.call: '%s', failed to locate TypeInfo for return value of type '%s'",
                                   op_str, oip->resultType().c_str());
                oh->ret_dsb=ti->buildValue();
                if(!oh->ret_dsb)
                        luaL_error(L, "Operation.call: '%s', failed to build DSB for return value of type '%s'",
                                   op_str, oip->resultType().c_str());

                oh->occ->ret(oh->ret_dsb);
                oh->is_void=false;
        } else {
                oh->is_void=true;
        }

        if(!oh->occ->ready())
                luaL_error(L, "Service.getOperation: OperationCallerC not ready!");

        return 1;
}

static int Service_getPort(lua_State *L)
{
        const char* name;
        PortInterface *pi;
        InputPortInterface *ipi;
        OutputPortInterface *opi;

        Service::shared_ptr srv;

        srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        name = luaL_checkstring(L, 2);

        pi = srv->getPort(name);
        if(!pi)
                luaL_error(L, "Service.getPort: service %s has no port %",
                           srv->getName().c_str(), name);

        /* input or output? */
        if ((ipi = dynamic_cast<InputPortInterface *> (pi)) != NULL)
                InputPort_push(L, ipi);
        else if ((opi = dynamic_cast<OutputPortInterface *> (pi)) != NULL)
                OutputPort_push(L, opi);
        else
                luaL_error(L, "Service.getPort: unknown port type returned");

        return 1;
}

static int Service_getProperty(lua_State *L)
{
        const char *name;
        PropertyBase *prop;

        Service::shared_ptr srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        name = luaL_checkstring(L, 2);

        prop = srv->getProperty(name);

        if(!prop)
                luaL_error(L, "%s failed. No such property", __FILE__);

        Property_push(L, prop);
        return 1;
}

static int Service_getPropertyNames(lua_State *L)
{
        Service::shared_ptr srv;
        srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        std::vector<std::string> plist = srv->properties()->list();
        push_vect_str(L, plist);
        return 1;
}

static int Service_getProperties(lua_State *L)
{
        Service::shared_ptr srv;
        srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        vector<PropertyBase*> props = srv->properties()->getProperties();

        int key = 1;
        lua_createtable(L, props.size(), 0);
        for(vector<PropertyBase*>::iterator it = props.begin(); it != props.end(); ++it) {
                Property_push(L, *it);
                lua_rawseti(L, -2, key++);
        }

        return 1;
}

static int Service_getAttribute(lua_State *L)
{
        const char *name;
        AttributeBase *prop;

        Service::shared_ptr srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        name = luaL_checkstring(L, 2);

        prop = srv->getAttribute(name);

        if(!prop)
                luaL_error(L, "%s failed. No such Attribute", __FILE__);

        Attribute_push(L, prop);
        return 1;
}

static int Service_getAttributeNames(lua_State *L)
{
        Service::shared_ptr srv;
        srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        std::vector<std::string> plist = srv->getAttributeNames();
        push_vect_str(L, plist);
        return 1;
}

static int Service_getAttributes(lua_State *L)
{
        Service::shared_ptr srv;
        srv = *(luaM_checkudata_mt(L, 1, "Service", Service::shared_ptr));
        vector<AttributeBase*> props = srv->getValues();

        int key = 1;
        lua_createtable(L, props.size(), 0);
        for(vector<AttributeBase*>::iterator it = props.begin(); it != props.end(); ++it) {
                Attribute_push(L, *it);
                lua_rawseti(L, -2, key++);
        }

        return 1;
}

static const struct luaL_Reg Service_f [] = {
        { "getName", Service_getName },
        { "doc", Service_doc },
        { "getProviderNames", Service_getProviderNames },
        { "getOperationNames", Service_getOperationNames },
        { "hasOperation", Service_hasOperation },
        { "getOperationInfo", Service_getOperationInfo },
        { "getPortNames", Service_getPortNames },
        { "provides", Service_provides },
        { "getOperation", Service_getOperation },
        { "getPort", Service_getPort },
        { "getProperty", Service_getProperty },
        { "getProperties", Service_getProperties },
        { "getPropertyNames", Service_getPropertyNames },
        { "getAttribute", Service_getAttribute },
        { "getAttributes", Service_getAttributes },
        { "getAttributeNames", Service_getAttributeNames },
        { NULL, NULL }
};

static const struct luaL_Reg Service_m [] = {
        { "getName", Service_getName },
        { "doc", Service_doc },
        { "getProviderNames", Service_getProviderNames },
        { "getOperationNames", Service_getOperationNames },
        { "hasOperation", Service_hasOperation },
        { "getOperationInfo", Service_getOperationInfo },
        { "getPortNames", Service_getPortNames },
        { "provides", Service_provides },
        { "getOperation", Service_getOperation },
        { "getPort", Service_getPort },
        { "getProperty", Service_getProperty },
        { "getProperties", Service_getProperties },
        { "getPropertyNames", Service_getPropertyNames },
        { "getAttribute", Service_getAttribute },
        { "getAttributes", Service_getAttributes },
        { "getAttributeNames", Service_getAttributeNames },
        { "__gc", GCMethod<Service::shared_ptr> },
        { NULL, NULL }
};

/***************************************************************
 * ServiceRequester
 ***************************************************************/

gen_push_bxptr(ServiceRequester_push, "ServiceRequester", ServiceRequester)

static int ServiceRequester_getRequestName(lua_State *L)
{
        ServiceRequester *sr;

        sr = *(luaM_checkudata_bx(L, 1, ServiceRequester));
        lua_pushstring(L, sr->getRequestName().c_str());
        return 1;
}

static int ServiceRequester_getRequesterNames(lua_State *L)
{
        ServiceRequester *sr;
        sr = *(luaM_checkudata_bx(L, 1, ServiceRequester));
        push_vect_str(L, sr->getRequesterNames());
        return 1;
}

static int ServiceRequester_ready(lua_State *L)
{
        int ret;
        ServiceRequester *sr;
        sr = *(luaM_checkudata_bx(L, 1, ServiceRequester));
        ret = sr->ready();
        lua_pushboolean(L, ret);
        return 1;
}

static int ServiceRequester_disconnect(lua_State *L)
{
        ServiceRequester *sr;
        sr = *(luaM_checkudata_bx(L, 1, ServiceRequester));
        sr->disconnect();
        return 0;
}

static int ServiceRequester_requires(lua_State *L)
{
        int argc, ret, i;
        const char* subsr_str;
        ServiceRequester *sr;
        ServiceRequester::shared_ptr subsr;

        sr = *(luaM_checkudata_bx(L, 1, ServiceRequester));
        argc = lua_gettop(L);

        /* return "this" if no args given */
        if(argc == 1) {
                ret = 1;
                goto out;
        }

        for(i=2; i<=argc; i++) {
                subsr_str = luaL_checkstring(L, i);
                subsr = sr->requires(subsr_str);
                if (subsr == 0)
                        luaL_error(L, "ServiceRequester: no required subservice %s of service %s",
                                   subsr_str, sr->getRequestName().c_str());
                else
                        ServiceRequester_push(L, subsr.get());
        }
        ret = argc - 1;

 out:
        return ret;
}

static const struct luaL_Reg ServiceRequester_f [] = {
        { "getRequestName", ServiceRequester_getRequestName },
        { "getRequesterNames", ServiceRequester_getRequesterNames },
        { "ready", ServiceRequester_ready },
        { "disconnect", ServiceRequester_disconnect },
        { "requires", ServiceRequester_requires },
        { NULL, NULL }
};

static const struct luaL_Reg ServiceRequester_m [] = {
        { "getRequestName", ServiceRequester_getRequestName },
        { "getRequesterNames", ServiceRequester_getRequesterNames },
        { "ready", ServiceRequester_ready },
        { "disconnect", ServiceRequester_disconnect },
        { "requires", ServiceRequester_requires },
        { NULL, NULL }
};


/***************************************************************
 * TaskContext (boxed)
 ***************************************************************/

gen_push_bxptr(TaskContext_push, "TaskContext", TaskContext)

static int TaskContext_getName(lua_State *L)
{
        const char *s;
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        s = tc->getName().c_str();
        lua_pushstring(L, s);
        return 1;
}

static int TaskContext_start(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        bool b = tc->start();
        lua_pushboolean(L, b);
        return 1;
}

static int TaskContext_stop(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        bool b = tc->stop();
        lua_pushboolean(L, b);
        return 1;
}

static int TaskContext_configure(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        bool ret = tc->configure();
        lua_pushboolean(L, ret);
        return 1;
}

static int TaskContext_activate(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        bool ret = tc->activate();
        lua_pushboolean(L, ret);
        return 1;
}

static int TaskContext_cleanup(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        bool ret = tc->cleanup();
        lua_pushboolean(L, ret);
        return 1;
}

static int TaskContext_error(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        tc->error();
        return 0;
}

static int TaskContext_recover(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        bool ret = tc->recover();
        lua_pushboolean(L, ret);
        return 1;
}

static int TaskContext_getState(lua_State *L)
{
        TaskCore::TaskState ts;
        TaskContext **tc = (TaskContext**) luaM_checkudata_bx(L, 1, TaskContext);
        ts = (*tc)->getTaskState();

        switch(ts) {
        case TaskCore::Init:            lua_pushstring(L, "Init"); break;
        case TaskCore::PreOperational:  lua_pushstring(L, "PreOperational"); break;
        case TaskCore::FatalError:      lua_pushstring(L, "FatalError"); break;
        case TaskCore::Exception:       lua_pushstring(L, "Exception"); break;
        case TaskCore::Stopped:         lua_pushstring(L, "Stopped"); break;
        case TaskCore::Running:         lua_pushstring(L, "Running"); break;
        case TaskCore::RunTimeError:    lua_pushstring(L, "RunTimeError"); break;
        default:                        lua_pushstring(L, "unknown");
        }
        return 1;
}

/* string-table getPeers(TaskContext self)*/
/* should better return array of TC's */
static int TaskContext_getPeers(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        std::vector<std::string> plist = tc->getPeerList();
        push_vect_str(L, plist);
        return 1;
}

/* bool addPeer(TaskContext self, TaskContext peer)*/
static int TaskContext_addPeer(lua_State *L)
{
        bool ret;
        TaskContext *self = *(luaM_checkudata_bx(L, 1, TaskContext));
        TaskContext *peer = *(luaM_checkudata_bx(L, 2, TaskContext));
        ret = self->addPeer(peer);
        lua_pushboolean(L, ret);
        return 1;
}

/* bool connectPeers(TaskContext self, TaskContext peer)*/
static int TaskContext_connectPeers(lua_State *L)
{
        bool ret;
        TaskContext *self = *(luaM_checkudata_bx(L, 1, TaskContext));
        TaskContext *peer = *(luaM_checkudata_bx(L, 2, TaskContext));
        ret = self->connectPeers(peer);
        lua_pushboolean(L, ret);
        return 1;
}

/* void removePeer(TaskContext self, string peer)*/
static int TaskContext_removePeer(lua_State *L)
{
        std::string peer;
        TaskContext *self = *(luaM_checkudata_bx(L, 1, TaskContext));
        peer = luaL_checkstring(L, 2);
        self->removePeer(peer);
        return 0;
}

/* TaskContext getPeer(string name) */
static int TaskContext_getPeer(lua_State *L)
{
        std::string strpeer;
        TaskContext *peer;
        TaskContext *self = *(luaM_checkudata_bx(L, 1, TaskContext));
        strpeer = luaL_checkstring(L, 2);
        peer = self->getPeer(strpeer);

        if(!peer) {
                luaL_error(L, "TaskContext.getPeer: no peer %s", strpeer.c_str());
                goto out;
        }

        TaskContext_push(L, peer);
 out:
        return 1;
}

static int TaskContext_getPortNames(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        std::vector<std::string> plist = tc->ports()->getPortNames();
        push_vect_str(L, plist);
        return 1;
}

static int TaskContext_addPort(lua_State *L)
{
        const char* name, *desc;
        PortInterface **pi;
        int argc = lua_gettop(L);
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));

        pi = (PortInterface**) luaL_testudata(L, 2, "InputPort");
        if(pi) goto check_name;

        pi = (PortInterface**) luaL_testudata(L, 2, "OutputPort");
        if(pi) goto check_name;

        return luaL_error(L, "addPort: invalid argument, not a Port");

 check_name:
        if(argc > 2) {
                name = luaL_checkstring(L, 3);
                (*pi)->setName(name);
        }

        if(argc > 3) {
                desc = luaL_checkstring(L, 4);
                (*pi)->doc(desc);
        }

        tc->ports()->addPort(**pi);
        return 0;
}

static int TaskContext_addEventPort(lua_State *L)
{
        const char* name, *desc;
        InputPortInterface **ipi;
        int argc = lua_gettop(L);
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));

        if((ipi = (InputPortInterface**) luaL_testudata(L, 2, "InputPort")) == NULL)
                return luaL_error(L, "addEventPort: invalid argument, not an InputPort");

        if(argc > 2) {
                name = luaL_checkstring(L, 3);
                (*ipi)->setName(name);
        }

        if(argc > 3) {
                desc = luaL_checkstring(L, 4);
                (*ipi)->doc(desc);
        }

        tc->ports()->addEventPort(**ipi);
        return 0;
}

static int TaskContext_getPort(lua_State *L)
{
        const char* name;
        PortInterface *pi;
        InputPortInterface *ipi;
        OutputPortInterface *opi;

        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        name = luaL_checkstring(L, 2);

        pi = tc->getPort(name);
        if(!pi)
                luaL_error(L, "TaskContext.getPort: no port %s for taskcontext %s",
                           name, tc->getName().c_str());

        /* input or output? */
        if ((ipi = dynamic_cast<InputPortInterface *> (pi)) != NULL)
                InputPort_push(L, ipi);
        else if ((opi = dynamic_cast<OutputPortInterface *> (pi)) != NULL)
                OutputPort_push(L, opi);
        else
                luaL_error(L, "TaskContext.getPort: unknown port returned");

        return 1;
}

static int TaskContext_removePort(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        const char *port = luaL_checkstring(L, 2);
        tc->ports()->removePort(port);
        return 0;
}

static int TaskContext_addProperty(lua_State *L)
{
        const char *name, *desc;
        int argc = lua_gettop(L);
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        PropertyBase *pb = *(luaM_checkudata_mt_bx(L, 2, "Property", PropertyBase));

        if(argc > 2) {
                name = luaL_checkstring(L, 3);
                pb->setName(name);
        }

        if(argc > 3) {
                desc = luaL_checkstring(L, 4);
                pb->setDescription(desc);
        }


        if(!tc->addProperty(*pb))
                luaL_error(L, "TaskContext.addProperty: failed to add property %s.",
                           pb->getName().c_str());

        return 0;
}

static int TaskContext_getProperty(lua_State *L)
{
        const char *name;
        PropertyBase *prop;

        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        name = luaL_checkstring(L, 2);

        prop = tc->getProperty(name);

        if(!prop)
                luaL_error(L, "%s failed. No such property", __FILE__);

        Property_push(L, prop);
        return 1;
}


static int TaskContext_getPropertyNames(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        std::vector<std::string> plist = tc->properties()->list();
        push_vect_str(L, plist);
        return 1;
}

static int TaskContext_getProperties(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        vector<PropertyBase*> props = tc->properties()->getProperties();

        int key = 1;
        lua_createtable(L, props.size(), 0);
        for(vector<PropertyBase*>::iterator it = props.begin(); it != props.end(); ++it) {
                Property_push(L, *it);
                lua_rawseti(L, -2, key++);
        }

        return 1;
}

static int TaskContext_removeProperty(lua_State *L)
{
        const char *name;
        PropertyBase *prop;

        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        name = luaL_checkstring(L, 2);

        prop = tc->getProperty(name);

        if(!prop)
                luaL_error(L, "%s failed. No such property", __FILE__);

        tc->properties()->remove(prop);
        return 0;
}

static int TaskContext_addAttribute(lua_State *L)
{
        int argc = lua_gettop(L);
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        AttributeBase *pb = *(luaM_checkudata_mt_bx(L, 2, "Attribute", AttributeBase));

        if(argc > 2) {
                const char *name = luaL_checkstring(L, 3);
                pb->setName(name);
        }

        if(!tc->addAttribute(*pb))
                luaL_error(L, "TaskContext.addAttribute: failed to add attribute %s.",
                           pb->getName().c_str());

        return 0;
}

static int TaskContext_getAttribute(lua_State *L)
{
        const char *name;
        AttributeBase *prop;

        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        name = luaL_checkstring(L, 2);

        prop = tc->getAttribute(name);

        if(!prop)
                luaL_error(L, "%s failed. No such Attribute", __FILE__);

        Attribute_push(L, prop);
        return 1;
}


static int TaskContext_getAttributeNames(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        std::vector<std::string> plist = tc->attributes()->getAttributeNames();
        push_vect_str(L, plist);
        return 1;
}

static int TaskContext_getAttributes(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        vector<AttributeBase*> props = tc->attributes()->getValues();

        int key = 1;
        lua_createtable(L, props.size(), 0);
        for(vector<AttributeBase*>::iterator it = props.begin(); it != props.end(); ++it) {
                Attribute_push(L, *it);
                lua_rawseti(L, -2, key++);
        }

        return 1;
}

static int TaskContext_removeAttribute(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        const char *name = luaL_checkstring(L, 2);

        if(!tc->attributes()->hasAttribute(name))
                luaL_error(L, "%s failed. No such attribute", __FILE__);

        tc->attributes()->removeAttribute(name);

        return 0;
}

static int TaskContext_getOps(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        std::vector<std::string> oplst = tc->operations()->getNames();
        push_vect_str(L, oplst);
        return 1;
}

/* returns restype, arity, table-of-arg-descr */
static int TaskContext_getOperationInfo(lua_State *L)
{
        int i=1;
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        const char *op = luaL_checkstring(L, 2);
        std::vector<ArgumentDescription> args;

        if(!tc->operations()->hasMember(op))
                luaL_error(L, "TaskContext.getOpInfo failed: no such operation");

        lua_pushstring(L, tc->operations()->getDescription(op).c_str()); /* description */
        lua_pushstring(L, tc->operations()->getResultType(op).c_str()); /* result type */
        lua_pushinteger(L, tc->operations()->getArity(op));             /* arity */

        args = tc->operations()->getArgumentList(op);

        lua_newtable(L);

        for (std::vector<ArgumentDescription>::iterator it = args.begin(); it != args.end(); it++) {
                lua_newtable(L);
                lua_pushstring(L, "name"); lua_pushstring(L, it->name.c_str()); lua_rawset(L, -3);
                lua_pushstring(L, "type"); lua_pushstring(L, it->type.c_str()); lua_rawset(L, -3);
                lua_pushstring(L, "desc"); lua_pushstring(L, it->description.c_str()); lua_rawset(L, -3);
                lua_rawseti(L, -2, i++);
        }

        return 4;
}

static int TaskContext_provides(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        Service::shared_ptr srv = tc->provides();

        if(srv == 0)
                luaL_error(L, "TaskContext.provides: no default service");

        /* forward to Serivce.provides */
        luaM_pushobject_mt(L, "Service", Service::shared_ptr)(srv);
        lua_replace(L, 1);
        return Service_provides(L);
}

static int TaskContext_getProviderNames(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        Service::shared_ptr srv = tc->provides();
        push_vect_str(L, srv->getProviderNames());
        return 1;
}

static int TaskContext_requires(lua_State *L)
{
        ServiceRequester::shared_ptr sr;
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        sr = tc->requires();

        if(!sr)
                luaL_error(L, "TaskContext.requires returned NULL");

        ServiceRequester_push(L, sr.get());
        lua_replace(L, 1);
        return ServiceRequester_requires(L);
}

static int TaskContext_connectServices(lua_State *L)
{
        int ret;
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        TaskContext *peer = *(luaM_checkudata_bx(L, 2, TaskContext));
        ret = tc->connectServices(peer);
        lua_pushboolean(L, ret);
        return 1;
}

static int TaskContext_hasOperation(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        Service::shared_ptr srv = tc->provides();

        if(srv == 0)
                luaL_error(L, "TaskContext.provides: no default service");

        /* forward to Serivce.hasOperation */
        luaM_pushobject_mt(L, "Service", Service::shared_ptr)(srv);
        lua_replace(L, 1);
        return Service_hasOperation(L);
}


static int TaskContext_getOperation(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        Service::shared_ptr srv = tc->provides();

        if(srv == 0)
                luaL_error(L, "TaskContext.getOperation: no default service");

        /* forward to Serivce.getOperation */
        luaM_pushobject_mt(L, "Service", Service::shared_ptr)(srv);
        lua_replace(L, 1);
        return Service_getOperation(L);
}

/*
 * SendHandle (required for send)
 */

static void SendStatus_push(lua_State *L, SendStatus ss)
{
        switch (ss) {
        case SendSuccess:  lua_pushstring(L, "SendSuccess"); break;
        case SendNotReady: lua_pushstring(L, "SendNotReady"); break;
        case SendFailure:  lua_pushstring(L, "SendFailure"); break;
        default:           lua_pushstring(L, "unkown");
        }
}

static int __SendHandle_collect(lua_State *L, bool block)
{
        unsigned int coll_argc;
        std::vector<DataSourceBase::shared_ptr> coll_args; /* temporarily store args */
        SendStatus ss;
        const types::TypeInfo *ti;
        OperationInterfacePart *oip;
        DataSourceBase::shared_ptr dsb, *dsbp;

        unsigned int argc = lua_gettop(L);
        SendHandleC *shc = luaM_checkudata_mt(L, 1, "SendHandle", SendHandleC);

        /* get orp pointer */
        oip = shc->getOrp();
        coll_argc = oip->collectArity();

        if(block && (argc == 1)) {
                // No args supplied, create them.
                for(unsigned int i=1; i<=coll_argc; i++) {
                        ti = oip->getCollectType(i);
                        dsb = ti->buildValue();
                        coll_args.push_back(dsb);
                        shc->arg(dsb);
                }
        } else if (argc-1 == coll_argc) {
                // args supplied, use them.
                if (!shc->ready()) {
                        for(unsigned int arg=2; arg<=argc; arg++) {
                                if ((dsbp = luaM_testudata_mt(L, arg, "Variable", DataSourceBase::shared_ptr)) != NULL)
                                        dsb = *dsbp;
                                else
                                        luaL_error(L, "SendHandle.collect: expected Variable argument at position %d", arg-1);
                                shc->arg(dsb);
                        }
                }
        } else {
                if (block) {
                        luaL_error(L, "SendHandle.collect: wrong number of args. expected either 0 or %d, got %d",
                                   coll_argc, argc-1);
                } else {
                        luaL_error(L, "SendHandle.collectIfDone: wrong number of args. expected %d, got %d",
                                   coll_argc, argc-1);
                }
        }

        if(block) ss = shc->collect();
        else ss = shc->collectIfDone();

        SendStatus_push(L, ss);

        if(ss == SendSuccess) {
                for (unsigned int i=0; i<coll_args.size(); i++)
                        Variable_push_coerce(L, coll_args[i]);

                /* SendStatus + collect args */
                return coll_args.size() + 1;

        } else {
                /* SendStatus only */
                return 1;
        }
}

static int SendHandle_collect(lua_State *L) { return __SendHandle_collect(L, true); }
static int SendHandle_collectIfDone(lua_State *L) { return __SendHandle_collect(L, false); }

static const struct luaL_Reg SendHandle_f [] = {
        { "collect", SendHandle_collect },
        { "collectIfDone", SendHandle_collectIfDone },
        { NULL, NULL }
};

static const struct luaL_Reg SendHandle_m [] = {
        { "collect", SendHandle_collect },
        { "collectIfDone", SendHandle_collectIfDone },
        { "__gc", GCMethod<SendHandleC> },
        { NULL, NULL }
};

/* only explicit destruction allowed */
static int TaskContext_del(lua_State *L)
{
        TaskContext *tc = *(luaM_checkudata_bx(L, 1, TaskContext));
        delete tc;

        /* this prevents calling rtt methods which would cause a crash */
        luaL_getmetatable(L, "__dead__");
        lua_setmetatable(L, -2);
        return 0;
}

static const struct luaL_Reg TaskContext_f [] = {
        { "getName", TaskContext_getName },
        { "start", TaskContext_start },
        { "stop", TaskContext_stop },
        { "configure", TaskContext_configure },
        { "activate", TaskContext_activate },
        { "cleanup", TaskContext_cleanup },
        { "error", TaskContext_error },
        { "recover", TaskContext_recover },
        { "getState", TaskContext_getState },
        { "getPeers", TaskContext_getPeers },
        { "addPeer", TaskContext_addPeer },
        { "removePeer", TaskContext_removePeer },
        { "getPeer", TaskContext_getPeer },
        { "getPortNames", TaskContext_getPortNames },
        { "addPort", TaskContext_addPort },
        { "addEventPort", TaskContext_addEventPort },
        { "getPort", TaskContext_getPort },
        { "removePort", TaskContext_removePort },
        { "addProperty", TaskContext_addProperty },
        { "getProperty", TaskContext_getProperty },
        { "getProperties", TaskContext_getProperties },
        { "getPropertyNames", TaskContext_getPropertyNames },
        { "removeProperty", TaskContext_removeProperty },
        { "addAttribute", TaskContext_addAttribute },
        { "getAttribute", TaskContext_getAttribute },
        { "getAttributes", TaskContext_getAttributes },
        { "getAttributeNames", TaskContext_getAttributeNames },
        { "removeAttribute", TaskContext_removeAttribute },
        { "getOps", TaskContext_getOps },
        { "getOpInfo", TaskContext_getOperationInfo },
        { "getOperationInfo", TaskContext_getOperationInfo },
        { "hasOperation", TaskContext_hasOperation },
        { "provides", TaskContext_provides },
        { "getProviderNames", TaskContext_getProviderNames },
        { "connectServices", TaskContext_connectServices },
        { "getOperation", TaskContext_getOperation },
        { "delete", TaskContext_del },
        { NULL, NULL}
};

static const struct luaL_Reg TaskContext_m [] = {
        { "getName", TaskContext_getName },
        { "start", TaskContext_start },
        { "stop", TaskContext_stop },
        { "configure", TaskContext_configure },
        { "activate", TaskContext_activate },
        { "cleanup", TaskContext_cleanup },
        { "error", TaskContext_error },
        { "recover", TaskContext_recover },
        { "getState", TaskContext_getState },
        { "getPeers", TaskContext_getPeers },
        { "addPeer", TaskContext_addPeer },
        { "connectPeers", TaskContext_connectPeers },
        { "removePeer", TaskContext_removePeer },
        { "getPeer", TaskContext_getPeer },
        { "getPortNames", TaskContext_getPortNames },
        { "addPort", TaskContext_addPort },
        { "addEventPort", TaskContext_addEventPort },
        { "getPort", TaskContext_getPort },
        { "removePort", TaskContext_removePort },
        { "addProperty", TaskContext_addProperty },
        { "getProperty", TaskContext_getProperty },
        { "getProperties", TaskContext_getProperties },
        { "getPropertyNames", TaskContext_getPropertyNames },
        { "addAttribute", TaskContext_addAttribute },
        { "getAttribute", TaskContext_getAttribute },
        { "getAttributes", TaskContext_getAttributes },
        { "getAttributeNames", TaskContext_getAttributeNames },
        { "removeAttribute", TaskContext_removeAttribute },
        { "removeProperty", TaskContext_removeProperty },
        { "getOps", TaskContext_getOps },
        { "getOpInfo", TaskContext_getOperationInfo },
        { "getOperationInfo", TaskContext_getOperationInfo },
        { "hasOperation", TaskContext_hasOperation },
        { "provides", TaskContext_provides },
        { "getProviderNames", TaskContext_getProviderNames },
        { "requires", TaskContext_requires },
        { "connectServices", TaskContext_connectServices },
        { "getOperation", TaskContext_getOperation },
        { "delete", TaskContext_del },
        // { "__index", TaskContext_index },
        /* we don't GC TaskContexts
         * { "__gc", GCMethod<TaskContext> }, */
        { NULL, NULL}
};

/*
 * Execution engine hook registration
 */

/* executable IF */
class EEHook : public base::ExecutableInterface
{
protected:
        std::string func;
        lua_State *L;
        TaskContext *tc; /* remember this to be able to print TC name
                            in error messages */
public:
        EEHook(lua_State *_L, std::string _func) { L = _L; func = _func; tc = __getTC(L); }
        bool execute() { return call_func(L, func.c_str(), tc, 1, 1); }
};

static int EEHook_new(lua_State *L)
{
        const char *func;
        func = luaL_checkstring(L, 1);
        luaM_pushobject(L, EEHook)(L, func);
        return 1;
}

static int EEHook_enable(lua_State *L)
{
        EEHook *eeh = luaM_checkudata(L, 1, EEHook);
        TaskContext *tc = __getTC(L);
        lua_pushboolean(L, tc->engine()->runFunction(eeh));
        return 1;
}

static int EEHook_disable(lua_State *L)
{       EEHook *eeh = luaM_checkudata(L, 1, EEHook);
        TaskContext *tc = __getTC(L);
        lua_pushboolean(L, tc->engine()->removeFunction(eeh));
        return 1;
}

#if 0
static int EEHook_gc(lua_State *L)
{
        EEHook_disable(L);
        lua_settop(L, 1);
        reinterpret_cast<EEHook*>(lua_touserdata(L, 1))->~EEHook();
        return 0;
}
#endif

static const struct luaL_Reg EEHook_f [] = {
        { "new", EEHook_new },
        { "enable", EEHook_enable },
        { "disable", EEHook_disable },
};


static const struct luaL_Reg EEHook_m [] = {
        { "enable", EEHook_enable },
        { "disable", EEHook_disable },
        /* { "__gc", EEHook_gc }, */
};


/*
 * Logger and miscellaneous
 */
static const char *const loglevels[] = {
        "Never", "Fatal", "Critical", "Error", "Warning", "Info", "Debug", "RealTime", NULL
};

static int Logger_setLogLevel(lua_State *L)
{
        Logger::LogLevel ll = (Logger::LogLevel) luaL_checkoption(L, 1, NULL, loglevels);
        log().setLogLevel(ll);
        return 0;
}

static int Logger_getLogLevel(lua_State *L)
{
        Logger::LogLevel ll = log().getLogLevel();

        switch(ll) {
        case Logger::Never:     lua_pushstring(L, "Never"); break;
        case Logger::Fatal:     lua_pushstring(L, "Fatal"); break;
        case Logger::Critical:  lua_pushstring(L, "Critical"); break;
        case Logger::Error:     lua_pushstring(L, "Error"); break;
        case Logger::Warning:   lua_pushstring(L, "Warning"); break;
        case Logger::Info:      lua_pushstring(L, "Info"); break;
        case Logger::Debug:     lua_pushstring(L, "Debug"); break;
        case Logger::RealTime:  lua_pushstring(L, "RealTime"); break;
        default:
                lua_pushstring(L, "unknown");
        }
        return 1;
}

static int Logger_log(lua_State *L)
{
        const char *mes;
        for(int i=1; i<=lua_gettop(L); i++) {
                mes = luaL_checkstring(L, i);
                Logger::log() << mes;
        }
        Logger::log() << endlog();
        return 0;
}

static int Logger_logl(lua_State *L)
{
        const char *mes;
        Logger::LogLevel ll = (Logger::LogLevel) luaL_checkoption(L, 1, NULL, loglevels);
        for(int i=2; i<=lua_gettop(L); i++) {
                mes = luaL_checkstring(L, i);
                Logger::log(ll) << mes;
        }
        Logger::log(ll) << endlog();
        return 0;
}

/* misc stuff */

static int getTime(lua_State *L)
{
        unsigned long nsec, sec;
        RTT::os::TimeService::nsecs total_nsec = TimeService::Instance()->getNSecs();
        sec =  total_nsec / 1000000000;
        nsec = total_nsec % 1000000000;
        lua_pushinteger(L, sec);
        lua_pushinteger(L, nsec);
        return 2;
}

static int rtt_sleep(lua_State *L)
{
        TIME_SPEC ts;
        ts.tv_sec = luaL_checknumber(L, 1);
        ts.tv_nsec = luaL_checknumber(L, 2);
        rtos_nanosleep(&ts, NULL);
        return 0;
}

static int getTC(lua_State *L)
{
        lua_pushstring(L, "this_TC");
        lua_rawget(L, LUA_REGISTRYINDEX);
        return 1;
}

static TaskContext* __getTC(lua_State *L)
{
        TaskContext *tc;
        getTC(L);
        tc = *(luaM_checkudata_bx(L, -1, TaskContext));
        lua_pop(L, 1);
        return tc;
}

/* access to the globals repository */
static int globals_getNames(lua_State *L)
{
        GlobalsRepository::shared_ptr gr = GlobalsRepository::Instance();
        push_vect_str(L, gr->getAttributeNames() );
        return 1;
}

static int globals_getProperties(lua_State *L)
{
        GlobalsRepository::shared_ptr gr = GlobalsRepository::Instance();
        push_vect_str(L, gr->properties()->list() );
        return 1;
}

static int globals_get(lua_State *L)
{
        const char *name;
        base::AttributeBase *ab;
        DataSourceBase::shared_ptr dsb;

        name = luaL_checkstring(L, 1);
        GlobalsRepository::shared_ptr gr = GlobalsRepository::Instance();

        ab = gr->getAttribute(name);

        if (ab)
                Variable_push_coerce(L, ab->getDataSource());
        else {
                base::PropertyBase *pb = gr->getProperty(name);
                if (pb)
                        Variable_push_coerce(L, pb->getDataSource());
                else
                        lua_pushnil(L);
  }

        return 1;
}

/* global service */
static int provides_global(lua_State *L)
{
        luaM_pushobject_mt(L, "Service", Service::shared_ptr)(GlobalService::Instance());
        lua_insert(L, 1);
        return Service_provides(L);
}

static int rtt_services(lua_State *L)
{
        push_vect_str(L, PluginLoader::Instance()->listServices());
        return 1;
}

static int rtt_typekits(lua_State *L)
{
        push_vect_str(L, PluginLoader::Instance()->listTypekits());
        return 1;
}

static int rtt_types(lua_State *L)
{
        push_vect_str(L, TypeInfoRepository::Instance()->getTypes());
        return 1;
}

static const struct luaL_Reg rtt_f [] = {
        {"getTime", getTime },
        {"sleep", rtt_sleep },
        {"getTC", getTC },
        {"globals_getNames", globals_getNames },
        {"globals_getProperties", globals_getProperties },
        {"globals_get", globals_get },
        {"provides", provides_global },
        {"services", rtt_services },
        {"typekits", rtt_typekits },
        {"types", rtt_types },
        {"setLogLevel", Logger_setLogLevel },
        {"getLogLevel", Logger_getLogLevel },
        {"log", Logger_log },
        {"logl", Logger_logl },
        {NULL, NULL}
};

extern "C" int luaopen_rtt(lua_State *L);

int luaopen_rtt(lua_State *L)
{
        lua_newtable(L);
        lua_replace(L, LUA_ENVIRONINDEX);

        luaL_newmetatable(L, "__dead__");

        /* register MyObj
         * 1. line creates metatable MyObj and registers name in registry
         * 2. line duplicates metatable
         * 3. line sets metatable[__index]=metatable
         *    (more precisely: table at -2 [__index] = top_of_stack, pops top of stack)
         * 4. line register methods in metatable
         * 5. line registers free functions in global mystuff.MyObj table
         */
        luaL_newmetatable(L, "TaskContext");
        lua_pushvalue(L, -1); /* duplicates metatable */
        lua_setfield(L, -2, "__index");
        luaL_register(L, NULL, TaskContext_m);
        luaL_register(L, "rtt.TaskContext", TaskContext_f);

        luaL_newmetatable(L, "Operation");
        lua_pushvalue(L, -1);
        lua_setfield(L, -2, "__index");
        luaL_register(L, NULL, Operation_m);
        luaL_register(L, "rtt.Operation", Operation_f);

        luaL_newmetatable(L, "Service");
        lua_pushvalue(L, -1);
        lua_setfield(L, -2, "__index");
        luaL_register(L, NULL, Service_m);
        luaL_register(L, "rtt.Service", Service_f);

        luaL_newmetatable(L, "ServiceRequester");
        lua_pushvalue(L, -1);
        lua_setfield(L, -2, "__index");
        luaL_register(L, NULL, ServiceRequester_m);
        luaL_register(L, "rtt.ServiceRequester", ServiceRequester_f);

        luaL_newmetatable(L, "SendHandle");
        lua_pushvalue(L, -1); /* duplicates metatable */
        lua_setfield(L, -2, "__index");
        luaL_register(L, NULL, SendHandle_m);
        luaL_register(L, "rtt.SendHandle", SendHandle_f);

        luaL_newmetatable(L, "InputPort");
        lua_pushvalue(L, -1); /* duplicates metatable */
        lua_setfield(L, -2, "__index");
        luaL_register(L, NULL, InputPort_m);
        luaL_register(L, "rtt.InputPort", InputPort_f);

        luaL_newmetatable(L, "OutputPort");
        lua_pushvalue(L, -1); /* duplicates metatable */
        lua_setfield(L, -2, "__index");
        luaL_register(L, NULL, OutputPort_m);
        luaL_register(L, "rtt.OutputPort", OutputPort_f);

        luaL_newmetatable(L, "Variable");
        lua_pushvalue(L, -1); /* duplicates metatable */
        lua_setfield(L, -2, "__index");
        luaL_register(L, NULL, Variable_m);
        luaL_register(L, "rtt.Variable", Variable_f);

        luaL_newmetatable(L, "Property");
        lua_pushvalue(L, -1); /* duplicates metatable */
        lua_setfield(L, -2, "__index");
        luaL_register(L, NULL, Property_m);
        luaL_register(L, "rtt.Property", Property_f);

        luaL_newmetatable(L, "Attribute");
        lua_pushvalue(L, -1); /* duplicates metatable */
        lua_setfield(L, -2, "__index");
        luaL_register(L, NULL, Attribute_m);
        luaL_register(L, "rtt.Attribute", Attribute_f);

        luaL_newmetatable(L, "EEHook");
        lua_pushvalue(L, -1); /* duplicates metatable */
        lua_setfield(L, -2, "__index");
        luaL_register(L, NULL, EEHook_m);
        luaL_register(L, "rtt.EEHook", EEHook_f);

        /* misc toplevel functions */
        luaL_register(L, "rtt", rtt_f);

        return 1;
}

/* store the TC to be returned by getTC() in registry */
int set_context_tc(TaskContext *tc, lua_State *L)
{
        TaskContext **new_tc;
        lua_pushstring(L, "this_TC");
        new_tc = (TaskContext**) lua_newuserdata(L, sizeof(TaskContext*));
        *new_tc = (TaskContext*) tc;
        luaL_getmetatable(L, "TaskContext");
        lua_setmetatable(L, -2);
        lua_rawset(L, LUA_REGISTRYINDEX);
        return 0;
}


/* call a zero arity function with a boolean return value
 * used to call various hooks */
bool call_func(lua_State *L, const char *fname, TaskContext *tc,
               int require_function, int require_result)
{
        bool ret = true;
        int num_res = (require_result != 0) ? 1 : 0;
        lua_getglobal(L, fname);

        if(lua_isnil(L, -1)) {
                lua_pop(L, 1);
                if(require_function)
                        luaL_error(L, "%s: no (required) Lua function %s", tc->getName().c_str(), fname);
                else
                        goto out;
        }

        if (lua_pcall(L, 0, num_res, 0) != 0) {
                Logger::log(Logger::Error) << "LuaComponent '"<< tc->getName()  <<"': error calling function "
                                           << fname << ": " << lua_tostring(L, -1) << endlog();
                lua_pop(L, 1);
                ret = false;
                goto out;
        }

        if(require_result) {
                if (!lua_isboolean(L, -1)) {
                        Logger::log(Logger::Error) << "LuaComponent '" << tc->getName() << "': " << fname
                                                   << " must return a bool but returned a "
                                                   << lua_typename(L, lua_type(L, -1)) << endlog();
                        lua_pop(L, 1);
                        ret = false;
                        goto out;
                }
                ret = lua_toboolean(L, -1);
                lua_pop(L, 1); /* pop result */
        }
 out:
        return ret;
}