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yields accross metamethods and for iterators (except for __concat)

pull/9/head
Roberto Ierusalimschy 16 years ago
parent
e02483dbc0
commit
f6978173e0
2 changed files with 84 additions and 40 deletions
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  1. 69
      ldo.c
  2. 55
      lvm.c

69
ldo.c
View File

@ -1,5 +1,5 @@
/*
** $Id: ldo.c,v 2.47 2008/08/13 17:02:42 roberto Exp roberto $
** $Id: ldo.c,v 2.48 2008/08/26 13:27:42 roberto Exp roberto $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@ -374,7 +374,6 @@ int luaD_poscall (lua_State *L, StkId firstResult) {
*/
void luaD_call (lua_State *L, StkId func, int nResults) {
global_State *g = G(L);
lua_assert(g->nCcalls >= L->baseCcalls);
if (++g->nCcalls >= LUAI_MAXCCALLS) {
if (g->nCcalls == LUAI_MAXCCALLS)
luaG_runerror(L, "C stack overflow");
@ -388,6 +387,55 @@ void luaD_call (lua_State *L, StkId func, int nResults) {
}
static void unroll (lua_State *L) {
for (;;) {
Instruction inst;
luaV_execute(L); /* execute up to higher C 'boundary' */
if (L->ci == L->base_ci) /* stack is empty? */
return; /* coroutine finished normally */
L->baseCcalls--; /* undo increment that allows yields */
inst = *(L->savedpc - 1); /* interrupted instruction */
switch (GET_OPCODE(inst)) { /* finish its execution */
case OP_ADD: case OP_SUB: case OP_MUL: case OP_DIV:
case OP_MOD: case OP_POW: case OP_UNM: case OP_LEN:
case OP_GETGLOBAL: case OP_GETTABLE: case OP_SELF: {
setobjs2s(L, L->base + GETARG_A(inst), --L->top);
break;
}
case OP_LE: case OP_LT: case OP_EQ: {
int res;
L->top--;
res = !l_isfalse(L->top);
/* cannot call metamethod with K operand */
lua_assert(!ISK(GETARG_B(inst)));
if (GET_OPCODE(inst) == OP_LE && /* "<=" using "<" instead? */
ttisnil(luaT_gettmbyobj(L, L->base + GETARG_B(inst), TM_LE)))
res = !res; /* invert result */
lua_assert(GET_OPCODE(*L->savedpc) == OP_JMP);
if (res == GETARG_A(inst))
L->savedpc += GETARG_sBx(*L->savedpc); /* jump */
L->savedpc++; /* skip jump instruction */
break;
}
case OP_SETGLOBAL: case OP_SETTABLE:
break; /* nothing to be done */
case OP_TFORLOOP: {
StkId cb = L->base + GETARG_A(inst) + 3;
L->top = L->ci->top;
lua_assert(GET_OPCODE(*L->savedpc) == OP_JMP);
if (!ttisnil(cb)) { /* continue loop? */
setobjs2s(L, cb - 1, cb); /* save control variable */
L->savedpc += GETARG_sBx(*L->savedpc); /* jump back */
}
L->savedpc++;
break;
}
default: lua_assert(0);
}
}
}
static void resume (lua_State *L, void *ud) {
StkId firstArg = cast(StkId, ud);
CallInfo *ci = L->ci;
@ -399,17 +447,17 @@ static void resume (lua_State *L, void *ud) {
else { /* resuming from previous yield */
lua_assert(L->status == LUA_YIELD);
L->status = LUA_OK;
if (!isLua(ci)) { /* `common' yield? */
if (isLua(ci)) /* yielded inside a hook? */
L->base = L->ci->base; /* just continue its execution */
else { /* 'common' yield */
/* finish interrupted execution of `OP_CALL' */
lua_assert(GET_OPCODE(*((ci-1)->savedpc - 1)) == OP_CALL ||
GET_OPCODE(*((ci-1)->savedpc - 1)) == OP_TAILCALL);
if (luaD_poscall(L, firstArg)) /* complete it... */
L->top = L->ci->top; /* and correct top if not multiple results */
}
else /* yielded inside a hook: just continue its execution */
L->base = L->ci->base;
}
luaV_execute(L);
unroll(L);
}
@ -432,10 +480,11 @@ LUA_API int lua_resume (lua_State *L, int nargs) {
return resume_error(L, "cannot resume non-suspended coroutine");
}
luai_userstateresume(L, nargs);
lua_assert(L->errfunc == 0 && L->baseCcalls == 0);
lua_assert(L->errfunc == 0);
if (G(L)->nCcalls >= LUAI_MAXCCALLS)
return resume_error(L, "C stack overflow");
L->baseCcalls = ++G(L)->nCcalls;
++G(L)->nCcalls; /* count resume */
L->baseCcalls += G(L)->nCcalls;
status = luaD_rawrunprotected(L, resume, L->top - nargs);
if (status != LUA_OK && status != LUA_YIELD) { /* error? */
L->status = cast_byte(status); /* mark thread as `dead' */
@ -443,11 +492,10 @@ LUA_API int lua_resume (lua_State *L, int nargs) {
L->ci->top = L->top;
}
else {
lua_assert(L->baseCcalls == G(L)->nCcalls);
lua_assert(status == L->status);
}
L->baseCcalls -= G(L)->nCcalls;
--G(L)->nCcalls;
L->baseCcalls = 0;
lua_unlock(L);
return status;
}
@ -456,6 +504,7 @@ LUA_API int lua_resume (lua_State *L, int nargs) {
LUA_API int lua_yield (lua_State *L, int nresults) {
luai_userstateyield(L, nresults);
lua_lock(L);
/*printf("yield: %d - %d\n", G(L)->nCcalls, L->baseCcalls);*/
if (G(L)->nCcalls > L->baseCcalls)
luaG_runerror(L, "attempt to yield across metamethod/C-call boundary");
L->base = L->top - nresults; /* protect stack slots below */

55
lvm.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lvm.c,v 2.76 2008/08/26 13:27:42 roberto Exp roberto $
** $Id: lvm.c,v 2.77 2008/09/09 13:53:02 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@ -76,31 +76,24 @@ static void traceexec (lua_State *L) {
}
static void callTMres (lua_State *L, StkId res, const TValue *f,
const TValue *p1, const TValue *p2) {
ptrdiff_t result = savestack(L, res);
setobj2s(L, L->top, f); /* push function */
setobj2s(L, L->top+1, p1); /* 1st argument */
setobj2s(L, L->top+2, p2); /* 2nd argument */
L->top += 3;
luaD_checkstack(L, 0);
luaD_call(L, L->top - 3, 1);
res = restorestack(L, result);
L->top--;
setobjs2s(L, res, L->top);
}
static void callTM (lua_State *L, const TValue *f, const TValue *p1,
const TValue *p2, const TValue *p3) {
setobj2s(L, L->top, f); /* push function */
setobj2s(L, L->top+1, p1); /* 1st argument */
setobj2s(L, L->top+2, p2); /* 2nd argument */
setobj2s(L, L->top+3, p3); /* 3th argument */
L->top += 4;
const TValue *p2, TValue *p3, int hasres) {
ptrdiff_t result = savestack(L, p3);
int oldbase = L->baseCcalls;
setobj2s(L, L->top++, f); /* push function */
setobj2s(L, L->top++, p1); /* 1st argument */
setobj2s(L, L->top++, p2); /* 2nd argument */
if (!hasres) /* no result? 'p3' is third argument */
setobj2s(L, L->top++, p3); /* 3th argument */
luaD_checkstack(L, 0);
luaD_call(L, L->top - 4, 0);
if (isLua(L->ci)) /* metamethod invoked from a Lua function? */
L->baseCcalls++; /* allow it to yield */
luaD_call(L, L->top - (4 - hasres), hasres);
L->baseCcalls = oldbase;
if (hasres) { /* if has result, move it to its place */
p3 = restorestack(L, result);
setobjs2s(L, p3, --L->top);
}
}
@ -121,7 +114,7 @@ void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) {
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX)))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm)) {
callTMres(L, val, tm, t, key);
callTM(L, tm, t, key, val, 1);
return;
}
t = tm; /* else repeat with `tm' */
@ -148,7 +141,7 @@ void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) {
else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX)))
luaG_typeerror(L, t, "index");
if (ttisfunction(tm)) {
callTM(L, tm, t, key, val);
callTM(L, tm, t, key, val, 0);
return;
}
t = tm; /* else repeat with `tm' */
@ -163,7 +156,7 @@ static int call_binTM (lua_State *L, const TValue *p1, const TValue *p2,
if (ttisnil(tm))
tm = luaT_gettmbyobj(L, p2, event); /* try second operand */
if (ttisnil(tm)) return 0;
callTMres(L, res, tm, p1, p2);
callTM(L, tm, p1, p2, res, 1);
return 1;
}
@ -190,7 +183,7 @@ static int call_orderTM (lua_State *L, const TValue *p1, const TValue *p2,
tm2 = luaT_gettmbyobj(L, p2, event);
if (!luaO_rawequalObj(tm1, tm2)) /* different metamethods? */
return -1;
callTMres(L, L->top, tm1, p1, p2);
callTM(L, tm1, p1, p2, L->top, 1);
return !l_isfalse(L->top);
}
@ -268,7 +261,7 @@ int luaV_equalval_ (lua_State *L, const TValue *t1, const TValue *t2) {
default: return gcvalue(t1) == gcvalue(t2);
}
if (tm == NULL) return 0; /* no TM? */
callTMres(L, L->top, tm, t1, t2); /* call TM */
callTM(L, tm, t1, t2, L->top, 1); /* call TM */
return !l_isfalse(L->top);
}
@ -336,7 +329,7 @@ static void objlen (lua_State *L, StkId ra, const TValue *rb) {
break;
}
}
callTMres(L, ra, tm, rb, luaO_nilobject);
callTM(L, tm, rb, luaO_nilobject, ra, 1);
}
@ -680,7 +673,9 @@ void luaV_execute (lua_State *L) {
setobjs2s(L, cb+1, ra+1);
setobjs2s(L, cb, ra);
L->top = cb+3; /* func. + 2 args (state and index) */
L->baseCcalls++;
Protect(luaD_call(L, cb, GETARG_C(i)));
L->baseCcalls--;
L->top = L->ci->top;
cb = RA(i) + 3; /* previous call may change the stack */
if (!ttisnil(cb)) { /* continue loop? */

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