/*
* Initialize keeper states
*
* If there is a problem, return an error message (NULL for okay).
*
* Note: Any problems would be design flaws; the created Lua state is left
* unclosed, because it does not really matter. In production code, this
* function never fails.
* settings table is at position 1 on the stack
*/
char const* init_keepers( lua_State* L)
{
int i;
PROPAGATE_ALLOCF_PREP( L);
STACK_CHECK( L);
lua_getfield( L, 1, "nb_keepers");
GNbKeepers = (int) lua_tointeger( L, -1);
lua_pop( L, 1);
STACK_END( L, 0);
assert( GNbKeepers >= 1);
GKeepers = malloc( GNbKeepers * sizeof( struct s_Keeper));
for( i = 0; i < GNbKeepers; ++ i)
{
lua_State* K = PROPAGATE_ALLOCF_ALLOC();
if( K == NULL)
{
(void) luaL_error( L, "init_keepers() failed while creating keeper state; out of memory");
}
STACK_CHECK( K);
// to see VM name in Decoda debugger
lua_pushliteral( K, "Keeper #");
lua_pushinteger( K, i + 1);
lua_concat( K, 2);
lua_setglobal( K, "decoda_name");
// create the fifos table in the keeper state
lua_pushlightuserdata( K, fifos_key);
lua_newtable( K);
lua_rawset( K, LUA_REGISTRYINDEX);
STACK_END( K, 0);
// we can trigger a GC from inside keeper_call(), where a keeper is acquired
// from there, GC can collect a linda, which would acquire the keeper again, and deadlock the thread.
MUTEX_RECURSIVE_INIT( &GKeepers[i].lock_);
GKeepers[i].L = K;
}
#if HAVE_KEEPER_ATEXIT_DESINIT
atexit( atexit_close_keepers);
#endif // HAVE_KEEPER_ATEXIT_DESINIT
return NULL; // ok
}
/*
* Initialize keeper states
*
* If there is a problem, returns NULL and pushes the error message on the stack
* else returns the keepers bookkeeping structure.
*
* Note: Any problems would be design flaws; the created Lua state is left
* unclosed, because it does not really matter. In production code, this
* function never fails.
* settings table is at position 1 on the stack
*/
void init_keepers( struct s_Universe* U, lua_State* L)
{
int i;
int nb_keepers;
void* allocUD;
lua_Alloc allocF = lua_getallocf( L, &allocUD);
STACK_CHECK( L); // L K
lua_getfield( L, 1, "nb_keepers"); // nb_keepers
nb_keepers = (int) lua_tointeger( L, -1);
lua_pop( L, 1); //
assert( nb_keepers >= 1);
// struct s_Keepers contains an array of 1 s_Keeper, adjust for the actual number of keeper states
{
size_t const bytes = sizeof( struct s_Keepers) + (nb_keepers - 1) * sizeof(struct s_Keeper);
U->keepers = (struct s_Keepers*) allocF( allocUD, NULL, 0, bytes);
if( U->keepers == NULL)
{
(void) luaL_error( L, "init_keepers() failed while creating keeper array; out of memory");
return;
}
memset( U->keepers, 0, bytes);
U->keepers->nb_keepers = nb_keepers;
}
for( i = 0; i < nb_keepers; ++ i) // keepersUD
{
lua_State* K = PROPAGATE_ALLOCF_ALLOC();
if( K == NULL)
{
(void) luaL_error( L, "init_keepers() failed while creating keeper states; out of memory");
return;
}
U->keepers->keeper_array[i].L = K;
// we can trigger a GC from inside keeper_call(), where a keeper is acquired
// from there, GC can collect a linda, which would acquire the keeper again, and deadlock the thread.
// therefore, we need a recursive mutex.
MUTEX_RECURSIVE_INIT( &U->keepers->keeper_array[i].keeper_cs);
STACK_CHECK( K);
// copy the universe pointer in the keeper itself
lua_pushlightuserdata( K, UNIVERSE_REGKEY);
lua_pushlightuserdata( K, U);
lua_rawset( K, LUA_REGISTRYINDEX);
STACK_MID( K, 0);
// make sure 'package' is initialized in keeper states, so that we have require()
// this because this is needed when transferring deep userdata object
luaL_requiref( K, "package", luaopen_package, 1); // package
lua_pop( K, 1); //
STACK_MID( K, 0);
serialize_require( U, K);
STACK_MID( K, 0);
// copy package.path and package.cpath from the source state
lua_getglobal( L, "package"); // "..." keepersUD package
if( !lua_isnil( L, -1))
{
// when copying with mode eLM_ToKeeper, error message is pushed at the top of the stack, not raised immediately
if( luaG_inter_copy_package( U, L, K, -1, eLM_ToKeeper))
{
// if something went wrong, the error message is at the top of the stack
lua_remove( L, -2); // error_msg
(void) lua_error( L);
return;
}
}
lua_pop( L, 1); //
STACK_MID( L, 0);
// attempt to call on_state_create(), if we have one and it is a C function
// (only support a C function because we can't transfer executable Lua code in keepers)
// will raise an error in L in case of problem
call_on_state_create( U, K, L, eLM_ToKeeper);
// to see VM name in Decoda debugger
lua_pushliteral( K, "Keeper #"); // "Keeper #"
lua_pushinteger( K, i + 1); // "Keeper #" n
lua_concat( K, 2); // "Keeper #n"
lua_setglobal( K, "decoda_name"); //
// create the fifos table in the keeper state
lua_pushlightuserdata( K, fifos_key); // fifo_key
lua_newtable( K); // fifo_key {}
lua_rawset( K, LUA_REGISTRYINDEX); //
STACK_END( K, 0);
}
STACK_END( L, 0);
}
