int
exec_setup_stack(struct lwp *l, struct exec_package *epp)
{
u_long max_stack_size;
u_long access_linear_min, access_size;
u_long noaccess_linear_min, noaccess_size;
#ifndef USRSTACK32
#define USRSTACK32 (0x00000000ffffffffL&~PGOFSET)
#endif
if (epp->ep_flags & EXEC_32) {
epp->ep_minsaddr = USRSTACK32;
max_stack_size = MAXSSIZ;
} else {
epp->ep_minsaddr = USRSTACK;
max_stack_size = MAXSSIZ;
}
epp->ep_ssize = l->l_proc->p_rlimit[RLIMIT_STACK].rlim_cur;
#ifdef PAX_ASLR
pax_aslr_stack(l, epp, &max_stack_size);
#endif /* PAX_ASLR */
l->l_proc->p_stackbase = epp->ep_minsaddr;
epp->ep_maxsaddr = (u_long)STACK_GROW(epp->ep_minsaddr,
max_stack_size);
/*
* set up commands for stack. note that this takes *two*, one to
* map the part of the stack which we can access, and one to map
* the part which we can't.
*
* arguably, it could be made into one, but that would require the
* addition of another mapping proc, which is unnecessary
*/
access_size = epp->ep_ssize;
access_linear_min = (u_long)STACK_ALLOC(epp->ep_minsaddr, access_size);
noaccess_size = max_stack_size - access_size;
noaccess_linear_min = (u_long)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr,
access_size), noaccess_size);
if (noaccess_size > 0 && noaccess_size <= MAXSSIZ) {
NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, noaccess_size,
noaccess_linear_min, NULL, 0, VM_PROT_NONE, VMCMD_STACK);
}
KASSERT(access_size > 0 && access_size <= MAXSSIZ);
NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, access_size,
access_linear_min, NULL, 0, VM_PROT_READ | VM_PROT_WRITE,
VMCMD_STACK);
return 0;
}
int keeper_push_linda_storage( struct s_Universe* U, lua_State* L, void* ptr, unsigned long magic_)
{
struct s_Keeper* K = keeper_acquire( U->keepers, magic_);
lua_State* KL = K ? K->L : NULL;
if( KL == NULL) return 0;
STACK_GROW( KL, 4);
STACK_CHECK( KL);
lua_pushlightuserdata( KL, fifos_key); // fifos_key
lua_rawget( KL, LUA_REGISTRYINDEX); // fifos
lua_pushlightuserdata( KL, ptr); // fifos ud
lua_rawget( KL, -2); // fifos storage
lua_remove( KL, -2); // storage
if( !lua_istable( KL, -1))
{
lua_pop( KL, 1); //
STACK_MID( KL, 0);
return 0;
}
// move data from keeper to destination state KEEPER MAIN
lua_pushnil( KL); // storage nil
STACK_GROW( L, 5);
STACK_CHECK( L);
lua_newtable( L); // out
while( lua_next( KL, -2)) // storage key fifo
{
keeper_fifo* fifo = prepare_fifo_access( KL, -1); // storage key fifo
lua_pushvalue( KL, -2); // storage key fifo key
luaG_inter_move( U, KL, L, 1, eLM_FromKeeper); // storage key fifo // out key
STACK_MID( L, 2);
lua_newtable( L); // out key keyout
luaG_inter_move( U, KL, L, 1, eLM_FromKeeper); // storage key // out key keyout fifo
lua_pushinteger( L, fifo->first); // out key keyout fifo first
STACK_MID( L, 5);
lua_setfield( L, -3, "first"); // out key keyout fifo
lua_pushinteger( L, fifo->count); // out key keyout fifo count
STACK_MID( L, 5);
lua_setfield( L, -3, "count"); // out key keyout fifo
lua_pushinteger( L, fifo->limit); // out key keyout fifo limit
STACK_MID( L, 5);
lua_setfield( L, -3, "limit"); // out key keyout fifo
lua_setfield( L, -2, "fifo"); // out key keyout
lua_rawset( L, -3); // out
STACK_MID( L, 1);
}
STACK_END( L, 1);
lua_pop( KL, 1); //
STACK_END( KL, 0);
keeper_release( K);
return 1;
}
// in: fifo
// out: remove the fifo from the stack, push as many items as required on the stack (function assumes they exist in sufficient number)
static void fifo_pop( lua_State* L, keeper_fifo* fifo, int count_)
{
int fifo_idx = lua_gettop( L); // ... fifo
int i;
// each iteration pushes a value on the stack!
STACK_GROW( L, count_ + 2);
// skip first item, we will push it last
for( i = 1; i < count_; ++ i)
{
int const at = fifo->first + i;
// push item on the stack
lua_rawgeti( L, fifo_idx, at); // ... fifo val
// remove item from the fifo
lua_pushnil( L); // ... fifo val nil
lua_rawseti( L, fifo_idx, at); // ... fifo val
}
// now process first item
{
int const at = fifo->first;
lua_rawgeti( L, fifo_idx, at); // ... fifo vals val
lua_pushnil( L); // ... fifo vals val nil
lua_rawseti( L, fifo_idx, at); // ... fifo vals val
lua_replace( L, fifo_idx); // ... vals
}
{
// avoid ever-growing indexes by resetting each time we detect the fifo is empty
int const new_count = fifo->count - count_;
fifo->first = (new_count == 0) ? 1 : (fifo->first + count_);
fifo->count = new_count;
}
}
const char *luaG_openlibs( lua_State *L, const char *libs ) {
const char *p;
unsigned len;
if (!libs) return NULL; // no libs, not even 'base'
// 'lua.c' stops GC during initialization so perhaps its a good idea. :)
//
lua_gc(L, LUA_GCSTOP, 0);
// Anything causes 'base' to be taken in
//
STACK_GROW(L,2);
lua_pushcfunction( L, luaopen_base );
lua_pushliteral( L, "" );
lua_call( L, 1, 0 );
for( p= libs; *p; p+=len ) {
len=0;
while (*p && !is_name_char(*p)) p++; // bypass delimiters
while (is_name_char(p[len])) len++; // bypass name
if (len && (!openlib( L, p, len )))
break;
}
lua_gc(L, LUA_GCRESTART, 0);
return *p ? p : NULL;
}
// in: fifo
// out: remove the fifo from the stack, push as many items as required on the stack (function assumes they exist in sufficient number)
static void fifo_pop( lua_State* L, keeper_fifo* fifo, int _count)
{
int fifo_idx = lua_gettop( L); // ... fifo
int i;
// each iteration pushes a value on the stack!
STACK_GROW( L, _count + 2);
// skip first item, we will push it last
for( i = 1; i < _count; ++ i)
{
int const at = fifo->first + i;
// push item on the stack
lua_rawgeti( L, fifo_idx, at); // ... fifo val
// remove item from the fifo
lua_pushnil( L); // ... fifo val nil
lua_rawseti( L, fifo_idx, at); // ... fifo val
}
// now process first item
{
int const at = fifo->first;
lua_rawgeti( L, fifo_idx, at); // ... fifo vals val
lua_pushnil( L); // ... fifo vals val nil
lua_rawseti( L, fifo_idx, at); // ... fifo vals val
lua_replace( L, fifo_idx); // ... vals
}
fifo->first += _count;
fifo->count -= _count;
}
/*
* Call a function ('func_name') in the keeper state, and pass on the returned
* values to 'L'.
*
* 'linda': deep Linda pointer (used only as a unique table key, first parameter)
* 'starting_index': first of the rest of parameters (none if 0)
*
* Returns: number of return values (pushed to 'L') or -1 in case of error
*/
int keeper_call( lua_State *K, keeper_api_t _func, lua_State *L, void *linda, uint_t starting_index)
{
int const args = starting_index ? (lua_gettop( L) - starting_index + 1) : 0;
int const Ktos = lua_gettop( K);
int retvals = -1;
STACK_GROW( K, 2);
PUSH_KEEPER_FUNC( K, _func);
lua_pushlightuserdata( K, linda);
if( (args == 0) || luaG_inter_copy( L, K, args) == 0) // L->K
{
lua_call( K, 1 + args, LUA_MULTRET);
retvals = lua_gettop( K) - Ktos;
if( (retvals > 0) && luaG_inter_move( K, L, retvals) != 0) // K->L
{
retvals = -1;
}
}
// whatever happens, restore the stack to where it was at the origin
lua_settop( K, Ktos);
return retvals;
}
// cause each keeper state to populate its database of transferable functions with those from the specified module
// do do this we simply require the module inside the keeper state, then populate the lookup database
void populate_keepers( lua_State* L)
{
size_t name_len;
char const* name = luaL_checklstring( L, -1, &name_len);
int i;
DEBUGSPEW_CODE( fprintf( stderr, INDENT_BEGIN "populate_keepers %s BEGIN\n" INDENT_END, name));
DEBUGSPEW_CODE( ++ debugspew_indent_depth);
for( i = 0; i < GNbKeepers; ++ i)
{
lua_State* K = GKeepers[i].L;
int res;
MUTEX_LOCK( &GKeepers[i].lock_);
STACK_CHECK( K);
STACK_GROW( K, 2);
lua_getglobal( K, "require");
lua_pushlstring( K, name, name_len);
res = lua_pcall( K, 1, 1, 0);
if( res != LUA_OK)
{
char const* err = luaL_checkstring( K, -1);
luaL_error( L, "error requiring '%s' in keeper state: %s", name, err);
}
// after requiring the module, register the functions it exported in our name<->function database
populate_func_lookup_table( K, -1, name);
lua_pop( K, 1);
STACK_END( K, 0);
MUTEX_UNLOCK( &GKeepers[i].lock_);
}
DEBUGSPEW_CODE( -- debugspew_indent_depth);
}
/*
* Does what the original 'push_registry_subtable' function did, but adds an optional mode argument to it
*/
void push_registry_subtable_mode( lua_State* L, void* key_, const char* mode_)
{
STACK_GROW( L, 3);
STACK_CHECK( L);
lua_pushlightuserdata( L, key_); // key
lua_rawget( L, LUA_REGISTRYINDEX); // {}|nil
if( lua_isnil( L, -1))
{
lua_pop( L, 1); //
lua_newtable( L); // {}
lua_pushlightuserdata( L, key_); // {} key
lua_pushvalue( L, -2); // {} key {}
// _R[key_] = {}
lua_rawset( L, LUA_REGISTRYINDEX); // {}
// Set its metatable if requested
if( mode_)
{
lua_newtable( L); // {} mt
lua_pushliteral( L, "__mode"); // {} mt "__mode"
lua_pushstring( L, mode_); // {} mt "__mode" mode
lua_rawset( L, -3); // {} mt
lua_setmetatable( L, -2); // {}
}
}
STACK_END( L, 1);
ASSERT_L( lua_istable( L, -1));
}
/*
* Create a deep userdata
*
* proxy_ud= deep_userdata( idfunc [, ...] )
*
* Creates a deep userdata entry of the type defined by 'idfunc'.
* Other parameters are passed on to the 'idfunc' "new" invocation.
*
* 'idfunc' must fulfill the following features:
*
* lightuserdata = idfunc( eDO_new [, ...] ) -- creates a new deep data instance
* void = idfunc( eDO_delete, lightuserdata ) -- releases a deep data instance
* tbl = idfunc( eDO_metatable ) -- gives metatable for userdata proxies
*
* Reference counting and true userdata proxying are taken care of for the
* actual data type.
*
* Types using the deep userdata system (and only those!) can be passed between
* separate Lua states via 'luaG_inter_move()'.
*
* Returns: 'proxy' userdata for accessing the deep data via 'luaG_todeep()'
*/
int luaG_newdeepuserdata( lua_State* L, luaG_IdFunction idfunc)
{
char const* errmsg;
DEEP_PRELUDE* prelude = DEEP_MALLOC( sizeof(DEEP_PRELUDE));
if( prelude == NULL)
{
return luaL_error( L, "couldn't not allocate deep prelude: out of memory");
}
prelude->refcount = 0; // 'push_deep_proxy' will lift it to 1
prelude->idfunc = idfunc;
STACK_GROW( L, 1);
STACK_CHECK( L);
{
int oldtop = lua_gettop( L);
prelude->deep = idfunc( L, eDO_new);
if( prelude->deep == NULL)
{
luaL_error( L, "idfunc(eDO_new) failed to create deep userdata (out of memory)");
}
if( lua_gettop( L) - oldtop != 0)
{
luaL_error( L, "Bad idfunc(eDO_new): should not push anything on the stack");
}
}
errmsg = push_deep_proxy( get_universe( L), L, prelude, eLM_LaneBody); // proxy
if( errmsg != NULL)
{
luaL_error( L, errmsg);
}
STACK_END( L, 1);
return 1;
}
/*
* Return the registered ID function for 'index' (deep userdata proxy),
* or NULL if 'index' is not a deep userdata proxy.
*/
static inline luaG_IdFunction get_idfunc( lua_State* L, int index, enum eLookupMode mode_)
{
// when looking inside a keeper, we are 100% sure the object is a deep userdata
if( mode_ == eLM_FromKeeper)
{
DEEP_PRELUDE** proxy = (DEEP_PRELUDE**) lua_touserdata( L, index);
// we can (and must) cast and fetch the internally stored idfunc
return (*proxy)->idfunc;
}
else
{
// essentially we are making sure that the metatable of the object we want to copy is stored in our metatable/idfunc database
// it is the only way to ensure that the userdata is indeed a deep userdata!
// of course, we could just trust the caller, but we won't
luaG_IdFunction ret;
STACK_GROW( L, 1);
STACK_CHECK( L);
if( !lua_getmetatable( L, index)) // deep ... metatable?
{
return NULL; // no metatable: can't be a deep userdata object!
}
// replace metatable with the idfunc pointer, if it is actually a deep userdata
get_deep_lookup( L); // deep ... idfunc|nil
ret = (luaG_IdFunction) lua_touserdata( L, -1); // NULL if not a userdata
lua_pop( L, 1);
STACK_END( L, 0);
return ret;
}
}
/*
* Call a function ('func_name') in the keeper state, and pass on the returned
* values to 'L'.
*
* 'linda': deep Linda pointer (used only as a unique table key, first parameter)
* 'starting_index': first of the rest of parameters (none if 0)
*
* Returns: number of return values (pushed to 'L') or -1 in case of error
*/
int keeper_call( lua_State *K, keeper_api_t _func, lua_State *L, void *linda, uint_t starting_index)
{
int const args = starting_index ? (lua_gettop( L) - starting_index + 1) : 0;
int const Ktos = lua_gettop( K);
int retvals = -1;
STACK_GROW( K, 2);
PUSH_KEEPER_FUNC( K, _func);
lua_pushlightuserdata( K, linda);
if( (args == 0) || luaG_inter_copy( L, K, args, eLM_ToKeeper) == 0) // L->K
{
lua_call( K, 1 + args, LUA_MULTRET);
retvals = lua_gettop( K) - Ktos;
// note that this can raise a luaL_error while the keeper state (and its mutex) is acquired
// this may interrupt a lane, causing the destruction of the underlying OS thread
// after this, another lane making use of this keeper can get an error code from the mutex-locking function
// when attempting to grab the mutex again (WINVER <= 0x400 does this, but locks just fine, I don't know about pthread)
if( (retvals > 0) && luaG_inter_move( K, L, retvals, eLM_FromKeeper) != 0) // K->L
{
retvals = -1;
}
}
// whatever happens, restore the stack to where it was at the origin
lua_settop( K, Ktos);
return retvals;
}
/*
* Push a registry subtable (keyed by unique 'token') onto the stack.
* If the subtable does not exist, it is created and chained.
*/
static
void push_registry_subtable( lua_State *L, void *token ) {
STACK_GROW(L,3);
STACK_CHECK(L)
lua_pushlightuserdata( L, token );
lua_rawget( L, LUA_REGISTRYINDEX );
//
// [-1]: nil/subtable
if (lua_isnil(L,-1)) {
lua_pop(L,1);
lua_newtable(L); // value
lua_pushlightuserdata( L, token ); // key
lua_pushvalue(L,-2);
//
// [-3]: value (2nd ref)
// [-2]: key
// [-1]: value
lua_rawset( L, LUA_REGISTRYINDEX );
}
STACK_END(L,1)
ASSERT_L( lua_istable(L,-1) );
}
// cause each keeper state to populate its database of transferable functions with those from the specified module
void populate_keepers( lua_State *L)
{
size_t name_len;
char const *name = luaL_checklstring( L, -1, &name_len);
size_t package_path_len;
char const *package_path;
size_t package_cpath_len;
char const *package_cpath;
int i;
// we need to make sure that package.path & package.cpath are the same in the keepers
// than what is currently in use when the module is required in the caller's Lua state
STACK_CHECK(L)
STACK_GROW( L, 3);
lua_getglobal( L, "package");
lua_getfield( L, -1, "path");
package_path = luaL_checklstring( L, -1, &package_path_len);
lua_getfield( L, -2, "cpath");
package_cpath = luaL_checklstring( L, -1, &package_cpath_len);
for( i = 0; i < GNbKeepers; ++ i)
{
lua_State *K = GKeepers[i].L;
int res;
MUTEX_LOCK( &GKeepers[i].lock_);
STACK_CHECK(K)
STACK_GROW( K, 2);
lua_getglobal( K, "package");
lua_pushlstring( K, package_path, package_path_len);
lua_setfield( K, -2, "path");
lua_pushlstring( K, package_cpath, package_cpath_len);
lua_setfield( K, -2, "cpath");
lua_pop( K, 1);
lua_getglobal( K, "require");
lua_pushlstring( K, name, name_len);
res = lua_pcall( K, 1, 0, 0);
if( res != 0)
{
char const *err = luaL_checkstring( K, -1);
luaL_error( L, "error requiring '%s' in keeper state: %s", name, err);
}
STACK_END(K, 0)
MUTEX_UNLOCK( &GKeepers[i].lock_);
}
lua_pop( L, 3);
STACK_END(L, 0)
}
// in: fifo
// out: ...|nothing
// expects exactly 1 value on the stack!
// currently only called with a count of 1, but this may change in the future
// function assumes that there is enough data in the fifo to satisfy the request
static void fifo_peek( lua_State* L, keeper_fifo* fifo, int _count)
{
int i;
STACK_GROW( L, _count);
for( i = 0; i < _count; ++ i)
{
lua_rawgeti( L, 1, fifo->first + i);
}
}
//in: linda_ud key [val]
int keepercall_set( lua_State* L)
{
STACK_GROW( L, 6);
// make sure we have a value on the stack
if( lua_gettop( L) == 2) // ud key val?
{
lua_pushnil( L); // ud key nil
}
// retrieve fifos associated with the linda
push_table( L, 1); // ud key val fifos
lua_replace( L, 1); // fifos key val
if( !lua_isnil( L, 3)) // set/replace contents stored at the specified key?
{
keeper_fifo* fifo;
lua_pushvalue( L, -2); // fifos key val key
lua_rawget( L, 1); // fifos key val fifo|nil
fifo = (keeper_fifo*) lua_touserdata( L, -1);
if( fifo == NULL) // might be NULL if we set a nonexistent key to nil
{
lua_pop( L, 1); // fifos key val
fifo_new( L); // fifos key val fifo
lua_pushvalue( L, 2); // fifos key val fifo key
lua_pushvalue( L, -2); // fifos key val fifo key fifo
lua_rawset( L, 1); // fifos key val fifo
}
else // the fifo exists, we just want to clear its contents
{
// empty the fifo for the specified key: replace uservalue with a virgin table, reset counters, but leave limit unchanged!
lua_newtable( L); // fifos key val fifo {}
lua_setuservalue( L, -2); // fifos key val fifo
fifo->first = 1;
fifo->count = 0;
}
fifo = prepare_fifo_access( L, -1);
lua_insert( L, -2); // fifos key fifo val
fifo_push( L, fifo, 1); // fifos key fifo
}
else // val == nil // fifos key nil
{
keeper_fifo* fifo;
lua_pop( L, 1); // fifos key
lua_rawget( L, 1); // fifos fifo|nil
// empty the fifo for the specified key: replace uservalue with a virgin table, reset counters, but leave limit unchanged!
fifo = (keeper_fifo*) lua_touserdata( L, -1);
if( fifo != NULL) // might be NULL if we set a nonexistent key to nil
{
lua_newtable( L); // fifos fifo {}
lua_setuservalue( L, -2); // fifos fifo
fifo->first = 1;
fifo->count = 0;
}
}
return 0;
}
int
darwin_exec_setup_stack(struct lwp *l, struct exec_package *epp)
{
u_long max_stack_size;
u_long access_linear_min, access_size;
u_long noaccess_linear_min, noaccess_size;
if (epp->ep_flags & EXEC_32) {
epp->ep_minsaddr = DARWIN_USRSTACK32;
max_stack_size = MAXSSIZ;
} else {
epp->ep_minsaddr = DARWIN_USRSTACK;
max_stack_size = MAXSSIZ;
}
epp->ep_maxsaddr = (u_long)STACK_GROW(epp->ep_minsaddr,
max_stack_size);
epp->ep_ssize = l->l_proc->p_rlimit[RLIMIT_STACK].rlim_cur;
/*
* set up commands for stack. note that this takes *two*, one to
* map the part of the stack which we can access, and one to map
* the part which we can't.
*
* arguably, it could be made into one, but that would require the
* addition of another mapping proc, which is unnecessary
*/
access_size = epp->ep_ssize;
access_linear_min = (u_long)STACK_ALLOC(epp->ep_minsaddr, access_size);
noaccess_size = max_stack_size - access_size;
noaccess_linear_min = (u_long)STACK_ALLOC(STACK_GROW(epp->ep_minsaddr,
access_size), noaccess_size);
if (noaccess_size > 0) {
NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, noaccess_size,
noaccess_linear_min, NULL, 0, VM_PROT_NONE, VMCMD_STACK);
}
KASSERT(access_size > 0);
NEW_VMCMD2(&epp->ep_vmcmds, vmcmd_map_zero, access_size,
access_linear_min, NULL, 0, VM_PROT_READ | VM_PROT_WRITE,
VMCMD_STACK);
return 0;
}
// in: nothing
// out: { first = 1, count = 0, limit = -1}
static void fifo_new( lua_State* L)
{
keeper_fifo* fifo;
STACK_GROW( L, 2);
fifo = (keeper_fifo*) lua_newuserdata( L, sizeof( keeper_fifo));
fifo->first = 1;
fifo->count = 0;
fifo->limit = -1;
lua_newtable( L);
lua_setuservalue( L, -2);
}
// in: linda_ud
int keepercall_clear( lua_State* L)
{
STACK_GROW( L, 3);
lua_pushlightuserdata( L, fifos_key); // ud fifos_key
lua_rawget( L, LUA_REGISTRYINDEX); // ud fifos
lua_pushvalue( L, 1); // ud fifos ud
lua_pushnil( L); // ud fifos ud nil
lua_rawset( L, -3); // ud fifos
lua_pop( L, 1); // ud
return 0;
}
// replaces the fifo ud by its uservalue on the stack
static keeper_fifo* prepare_fifo_access( lua_State* L, int idx)
{
keeper_fifo* fifo = (keeper_fifo*) lua_touserdata( L, idx);
if( fifo != NULL)
{
idx = lua_absindex( L, idx);
STACK_GROW( L, 1);
// we can replace the fifo userdata in the stack without fear of it being GCed, there are other references around
lua_getuservalue( L, idx);
lua_replace( L, idx);
}
return fifo;
}
/*
* Sets up [-1]<->[-2] two-way lookups, and ensures the lookup table exists.
* Pops the both values off the stack.
*/
static void set_deep_lookup( lua_State* L)
{
STACK_GROW( L, 3);
STACK_CHECK( L); // a b
push_registry_subtable( L, DEEP_LOOKUP_KEY); // a b {}
STACK_MID( L, 1);
lua_insert( L, -3); // {} a b
lua_pushvalue( L, -1); // {} a b b
lua_pushvalue( L,-3); // {} a b b a
lua_rawset( L, -5); // {} a b
lua_rawset( L, -3); // {}
lua_pop( L, 1); //
STACK_END( L, -2);
}
/*
* Pops the key (metatable or idfunc) off the stack, and replaces with the
* deep lookup value (idfunc/metatable/nil).
*/
static void get_deep_lookup( lua_State* L)
{
STACK_GROW( L, 1);
STACK_CHECK( L); // a
lua_pushlightuserdata( L, DEEP_LOOKUP_KEY); // a DLK
lua_rawget( L, LUA_REGISTRYINDEX); // a {}
if( !lua_isnil( L, -1))
{
lua_insert( L, -2); // {} a
lua_rawget( L, -2); // {} b
}
lua_remove( L, -2); // a|b
STACK_END( L, 0);
}
/*
* Sets up [-1]<->[-2] two-way lookups, and ensures the lookup table exists.
* Pops the both values off the stack.
*/
void set_deep_lookup( lua_State *L ) {
STACK_GROW(L,3);
STACK_CHECK(L)
#if 1
push_registry_subtable( L, DEEP_LOOKUP_KEY );
#else
/* ..to be removed.. */
lua_pushlightuserdata( L, DEEP_LOOKUP_KEY );
lua_rawget( L, LUA_REGISTRYINDEX );
if (lua_isnil(L,-1)) {
// First time here; let's make the lookup
//
lua_pop(L,1);
lua_newtable(L);
lua_pushlightuserdata( L, DEEP_LOOKUP_KEY );
lua_pushvalue(L,-2);
//
// [-3]: {} (2nd ref)
// [-2]: DEEP_LOOKUP_KEY
// [-1]: {}
lua_rawset( L, LUA_REGISTRYINDEX );
//
// [-1]: lookup table (empty)
}
#endif
STACK_MID(L,1)
lua_insert(L,-3);
// [-3]: lookup table
// [-2]: A
// [-1]: B
lua_pushvalue( L,-1 ); // B
lua_pushvalue( L,-3 ); // A
lua_rawset( L, -5 ); // B->A
lua_rawset( L, -3 ); // A->B
lua_pop( L,1 );
STACK_END(L,-2)
}
static bool_t openlib( lua_State *L, const char *name, size_t len ) {
unsigned i;
bool_t all= strncmp( name, "*", len ) == 0;
for( i=0; libs[i].name; i++ ) {
if (all || (strncmp(name, libs[i].name, len) ==0)) {
if (libs[i].func) {
STACK_GROW(L,2);
lua_pushcfunction( L, libs[i].func );
lua_pushstring( L, libs[i].name );
lua_call( L, 1, 0 );
}
if (!all) return TRUE;
}
}
return all;
}
void luaG_dump( lua_State* L ) {
int top= lua_gettop(L);
int i;
fprintf( stderr, "\n\tDEBUG STACK:\n" );
if (top==0)
fprintf( stderr, "\t(none)\n" );
for( i=1; i<=top; i++ ) {
int type= lua_type( L, i );
fprintf( stderr, "\t[%d]= (%s) ", i, lua_typename(L,type) );
// Print item contents here...
//
// Note: this requires 'tostring()' to be defined. If it is NOT,
// enable it for more debugging.
//
STACK_CHECK(L)
STACK_GROW( L, 2 )
lua_getglobal( L, "tostring" );
//
// [-1]: tostring function, or nil
if (!lua_isfunction(L,-1)) {
fprintf( stderr, "('tostring' not available)" );
} else {
lua_pushvalue( L, i );
lua_call( L, 1 /*args*/, 1 /*retvals*/ );
// Don't trust the string contents
//
fprintf( stderr, "%s", lua_tostring(L,-1) );
}
lua_pop(L,1);
STACK_END(L,0)
fprintf( stderr, "\n" );
}
fprintf( stderr, "\n" );
}
/*
* Get a unique ID for metatable at [i].
*/
static
uint_t get_mt_id( lua_State *L, int i ) {
static uint_t last_id= 0;
uint_t id;
i= STACK_ABS(L,i);
STACK_GROW(L,3);
STACK_CHECK(L)
push_registry_subtable( L, REG_MTID );
lua_pushvalue(L, i);
lua_rawget( L, -2 );
//
// [-2]: reg[REG_MTID]
// [-1]: nil/uint
id= lua_tointeger(L,-1); // 0 for nil
lua_pop(L,1);
STACK_MID(L,1)
if (id==0) {
MUTEX_LOCK( &mtid_lock );
id= ++last_id;
MUTEX_UNLOCK( &mtid_lock );
/* Create two-way references: id_uint <-> table
*/
lua_pushvalue(L,i);
lua_pushinteger(L,id);
lua_rawset( L, -3 );
lua_pushinteger(L,id);
lua_pushvalue(L,i);
lua_rawset( L, -3 );
}
lua_pop(L,1); // remove 'reg[REG_MTID]' reference
STACK_END(L,0)
return id;
}
static void push_table( lua_State* L, int idx)
{
STACK_GROW( L, 4);
STACK_CHECK( L);
idx = lua_absindex( L, idx);
lua_pushlightuserdata( L, fifos_key); // ud fifos_key
lua_rawget( L, LUA_REGISTRYINDEX); // ud fifos
lua_pushvalue( L, idx); // ud fifos ud
lua_rawget( L, -2); // ud fifos fifos[ud]
STACK_MID( L, 2);
if( lua_isnil( L, -1))
{
lua_pop( L, 1); // ud fifos
// add a new fifos table for this linda
lua_newtable( L); // ud fifos fifos[ud]
lua_pushvalue( L, idx); // ud fifos fifos[ud] ud
lua_pushvalue( L, -2); // ud fifos fifos[ud] ud fifos[ud]
lua_rawset( L, -4); // ud fifos fifos[ud]
}
lua_remove( L, -2); // ud fifos[ud]
STACK_END( L, 1);
}
/*
* Pops the key (metatable or idfunc) off the stack, and replaces with the
* deep lookup value (idfunc/metatable/nil).
*/
void get_deep_lookup( lua_State *L ) {
STACK_GROW(L,1);
STACK_CHECK(L)
lua_pushlightuserdata( L, DEEP_LOOKUP_KEY );
lua_rawget( L, LUA_REGISTRYINDEX );
if (!lua_isnil(L,-1)) {
// [-2]: key (metatable or idfunc)
// [-1]: lookup table
lua_insert( L, -2 );
lua_rawget( L, -2 );
// [-2]: lookup table
// [-1]: value (metatable / idfunc / nil)
}
lua_remove(L,-2);
// remove lookup, or unused key
STACK_END(L,0)
}
/*
* Return the registered ID function for 'index' (deep userdata proxy),
* or NULL if 'index' is not a deep userdata proxy.
*/
static
lua_CFunction get_idfunc( lua_State *L, int index ) {
lua_CFunction ret;
index= STACK_ABS(L,index);
STACK_GROW(L,1);
STACK_CHECK(L)
if (!lua_getmetatable( L, index ))
return NULL; // no metatable
// [-1]: metatable of [index]
get_deep_lookup(L);
//
// [-1]: idfunc/nil
ret= lua_tocfunction(L,-1);
lua_pop(L,1);
STACK_END(L,0)
return ret;
}
/*
* Create a deep userdata
*
* proxy_ud= deep_userdata( idfunc [, ...] )
*
* Creates a deep userdata entry of the type defined by 'idfunc'.
* Other parameters are passed on to the 'idfunc' "new" invocation.
*
* 'idfunc' must fulfill the following features:
*
* lightuserdata= idfunc( "new" [, ...] ) -- creates a new deep data instance
* void= idfunc( "delete", lightuserdata ) -- releases a deep data instance
* tbl= idfunc( "metatable" ) -- gives metatable for userdata proxies
*
* Reference counting and true userdata proxying are taken care of for the
* actual data type.
*
* Types using the deep userdata system (and only those!) can be passed between
* separate Lua states via 'luaG_inter_move()'.
*
* Returns: 'proxy' userdata for accessing the deep data via 'luaG_todeep()'
*/
int luaG_deep_userdata( lua_State *L ) {
lua_CFunction idfunc= lua_tocfunction( L,1 );
int pushed;
DEEP_PRELUDE *prelude= DEEP_MALLOC( sizeof(DEEP_PRELUDE) );
ASSERT_L(prelude);
prelude->refcount= 0; // 'luaG_push_proxy' will lift it to 1
STACK_GROW(L,1);
STACK_CHECK(L)
// Replace 'idfunc' with "new" in the stack (keep possible other params)
//
lua_remove(L,1);
lua_pushliteral( L, "new" );
lua_insert(L,1);
// lightuserdata= idfunc( "new" [, ...] )
//
pushed= idfunc(L);
if ((pushed!=1) || lua_type(L,-1) != LUA_TLIGHTUSERDATA)
luaL_error( L, "Bad idfunc on \"new\": did not return light userdata" );
prelude->deep= lua_touserdata(L,-1);
ASSERT_L(prelude->deep);
lua_pop(L,1); // pop deep data
luaG_push_proxy( L, idfunc, prelude );
//
// [-1]: proxy userdata
STACK_END(L,1)
return 1;
}
static void inter_copy_func( lua_State *L2, uint_t L2_cache_i, lua_State *L, uint_t i ) {
lua_CFunction cfunc= lua_tocfunction( L,i );
unsigned n;
ASSERT_L( L2_cache_i != 0 );
STACK_GROW(L,2);
STACK_CHECK(L)
if (!cfunc) { // Lua function
luaL_Buffer b;
const char *s;
size_t sz;
int tmp;
const char *name= NULL;
#if 0
// "To get information about a function you push it onto the
// stack and start the what string with the character '>'."
//
{ lua_Debug ar;
lua_pushvalue( L, i );
lua_getinfo(L, ">n", &ar); // fills 'name' and 'namewhat', pops function
name= ar.namewhat;
fprintf( stderr, "NAME: %s\n", name ); // just gives NULL
}
#endif
// 'lua_dump()' needs the function at top of stack
//
if (i!=-1) lua_pushvalue( L, i );
luaL_buffinit(L,&b);
tmp= lua_dump(L, buf_writer, &b);
ASSERT_L(tmp==0);
//
// "value returned is the error code returned by the last call
// to the writer" (and we only return 0)
luaL_pushresult(&b); // pushes dumped string on 'L'
s= lua_tolstring(L,-1,&sz);
ASSERT_L( s && sz );
if (i!=-1) lua_remove( L, -2 );
// Note: Line numbers seem to be taken precisely from the
// original function. 'name' is not used since the chunk
// is precompiled (it seems...).
//
// TBD: Can we get the function's original name through, as well?
//
if (luaL_loadbuffer(L2, s, sz, name) != 0) {
// chunk is precompiled so only LUA_ERRMEM can happen
// "Otherwise, it pushes an error message"
//
STACK_GROW( L,1 );
luaL_error( L, "%s", lua_tostring(L2,-1) );
}
lua_pop(L,1); // remove the dumped string
STACK_MID(L,0)
}
