commit f6978173e03fdbe5536887b08beb53884f7c1a18
parent e02483dbc031ca0cdba17cb511c1e674551f90c5
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Tue, 28 Oct 2008 14:52:53 -0200
yields accross metamethods and for iterators (except for __concat)
Diffstat:
| M | ldo.c | | | 69 | +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---------- |
| M | lvm.c | | | 55 | +++++++++++++++++++++++++------------------------------ |
2 files changed, 84 insertions(+), 40 deletions(-)
diff --git a/ldo.c b/ldo.c
@@ -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 */
diff --git a/lvm.c b/lvm.c
@@ -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? */
