/*
* void= mt.__gc( proxy_ud )
*
* End of life for a proxy object; reduce the deep reference count and clean
* it up if reaches 0.
*/
static
int deep_userdata_gc( lua_State *L ) {
DEEP_PRELUDE **proxy= (DEEP_PRELUDE**)lua_touserdata( L, 1 );
DEEP_PRELUDE *p= *proxy;
int v;
*proxy= 0; // make sure we don't use it any more
MUTEX_LOCK( &deep_lock );
v= --(p->refcount);
MUTEX_UNLOCK( &deep_lock );
if (v==0) {
int pushed;
// Call 'idfunc( "delete", deep_ptr )' to make deep cleanup
//
lua_CFunction idfunc= get_idfunc(L,1);
ASSERT_L(idfunc);
lua_settop(L,0); // clean stack so we can call 'idfunc' directly
// void= idfunc( "delete", lightuserdata )
//
lua_pushliteral( L, "delete" );
lua_pushlightuserdata( L, p->deep );
pushed= idfunc(L);
if (pushed)
luaL_error( L, "Bad idfunc on \"delete\": returned something" );
DEEP_FREE( (void*)p );
}
return 0;
}
/*
* Access deep userdata through a proxy.
*
* Reference count is not changed, and access to the deep userdata is not
* serialized. It is the module's responsibility to prevent conflicting usage.
*/
void *luaG_todeep( lua_State *L, lua_CFunction idfunc, int index ) {
DEEP_PRELUDE **proxy;
STACK_CHECK(L)
if (get_idfunc(L,index) != idfunc)
return NULL; // no metatable, or wrong kind
proxy= (DEEP_PRELUDE**)lua_touserdata( L, index );
STACK_END(L,0)
return (*proxy)->deep;
}
/*
* Access deep userdata through a proxy.
*
* Reference count is not changed, and access to the deep userdata is not
* serialized. It is the module's responsibility to prevent conflicting usage.
*/
void* luaG_todeep( lua_State* L, luaG_IdFunction idfunc, int index)
{
DEEP_PRELUDE** proxy;
STACK_CHECK( L);
// ensure it is actually a deep userdata
if( get_idfunc( L, index, eLM_LaneBody) != idfunc)
{
return NULL; // no metatable, or wrong kind
}
proxy = (DEEP_PRELUDE**) lua_touserdata( L, index);
STACK_END( L, 0);
return (*proxy)->deep;
}
/*
* Copy deep userdata between two separate Lua states (from L to L2)
*
* Returns:
* the id function of the copied value, or NULL for non-deep userdata
* (not copied)
*/
luaG_IdFunction copydeep( struct s_Universe* U, lua_State* L, lua_State* L2, int index, enum eLookupMode mode_)
{
char const* errmsg;
luaG_IdFunction idfunc = get_idfunc( L, index, mode_);
if( idfunc == NULL)
{
return NULL; // not a deep userdata
}
errmsg = push_deep_proxy( U, L2, *(DEEP_PRELUDE**) lua_touserdata( L, index), mode_);
if( errmsg != NULL)
{
// raise the error in the proper state (not the keeper)
lua_State* errL = (mode_ == eLM_FromKeeper) ? L2 : L;
luaL_error( errL, errmsg);
}
return idfunc;
}
/*
* Copy deep userdata between two separate Lua states.
*
* Returns:
* the id function of the copied value, or NULL for non-deep userdata
* (not copied)
*/
static
lua_CFunction luaG_copydeep( lua_State *L, lua_State *L2, int index ) {
DEEP_PRELUDE **proxy;
DEEP_PRELUDE *p;
lua_CFunction idfunc;
idfunc= get_idfunc( L, index );
if (!idfunc) return NULL; // not a deep userdata
// Increment reference count
//
proxy= (DEEP_PRELUDE**)lua_touserdata( L, index );
p= *proxy;
luaG_push_proxy( L2, idfunc, p );
//
// L2 [-1]: proxy userdata
return idfunc;
}
