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back to 'CallInfo' (no gains with its removal)

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This commit is contained in:
Roberto Ierusalimschy
2017-11-07 11:25:26 -02:00
parent 5a3f26f855
commit ad0704e40c
13 changed files with 394 additions and 370 deletions
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190
ldo.c
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@@ -1,5 +1,5 @@
/*
** $Id: ldo.c,v 2.168 2017/11/03 20:41:05 roberto Exp roberto $
** $Id: ldo.c,v 2.165 2017/11/02 11:28:56 roberto Exp $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@@ -123,8 +123,8 @@ l_noret luaD_throw (lua_State *L, int errcode) {
else { /* no handler at all; abort */
if (g->panic) { /* panic function? */
seterrorobj(L, errcode, L->top); /* assume EXTRA_STACK */
if (functop(L->func) < L->top) /* check invariant */
setfunctop(L->func, L->top);
if (L->ci->top < L->top)
L->ci->top = L->top; /* pushing msg. can break this invariant */
lua_unlock(L);
g->panic(L); /* call panic function (last chance to jump out) */
}
@@ -157,11 +157,15 @@ int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) {
** ===================================================================
*/
static void correctstack (lua_State *L, StkId oldstack) {
CallInfo *ci;
UpVal *up;
L->top = (L->top - oldstack) + L->stack;
L->func = (L->func - oldstack) + L->stack;
for (up = L->openupval; up != NULL; up = up->u.open.next)
up->v = s2v((uplevel(up) - oldstack) + L->stack);
for (ci = L->ci; ci != NULL; ci = ci->previous) {
ci->top = (ci->top - oldstack) + L->stack;
ci->func = (ci->func - oldstack) + L->stack;
}
}
@@ -203,11 +207,10 @@ void luaD_growstack (lua_State *L, int n) {
static int stackinuse (lua_State *L) {
CallInfo *ci;
StkId lim = L->top;
StkId func = L->func;
for (; func->stkci.previous != 0; func -= func->stkci.previous) {
if (lim < functop(func))
lim = functop(func);
for (ci = L->ci; ci != NULL; ci = ci->previous) {
if (lim < ci->top) lim = ci->top;
}
lua_assert(lim <= L->stack_last);
return cast_int(lim - L->stack) + 1; /* part of stack in use */
@@ -219,6 +222,10 @@ void luaD_shrinkstack (lua_State *L) {
int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK;
if (goodsize > LUAI_MAXSTACK)
goodsize = LUAI_MAXSTACK; /* respect stack limit */
if (L->stacksize > LUAI_MAXSTACK) /* had been handling stack overflow? */
luaE_freeCI(L); /* free all CIs (list grew because of an error) */
else
luaE_shrinkCI(L); /* shrink list */
/* if thread is currently not handling a stack overflow and its
good size is smaller than current size, shrink its stack */
if (inuse <= (LUAI_MAXSTACK - EXTRA_STACK) &&
@@ -245,46 +252,40 @@ void luaD_inctop (lua_State *L) {
void luaD_hook (lua_State *L, int event, int line) {
lua_Hook hook = L->hook;
if (hook && L->allowhook) { /* make sure there is a hook */
CallInfo *ci = L->ci;
ptrdiff_t top = savestack(L, L->top);
int origframesize = L->func->stkci.framesize;
int tmpframesize; /* frame size to run hook */
ptrdiff_t ci_top = savestack(L, ci->top);
lua_Debug ar;
ar.event = event;
ar.currentline = line;
ar.i_actf = L->func - L->stack;
ar.i_actL = L;
ar.i_ci = ci;
luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */
tmpframesize = L->top - L->func + LUA_MINSTACK;
if (tmpframesize > origframesize) /* need to grow frame? */
L->func->stkci.framesize = tmpframesize;
lua_assert(functop(L->func) <= L->stack_last);
ci->top = L->top + LUA_MINSTACK;
lua_assert(ci->top <= L->stack_last);
L->allowhook = 0; /* cannot call hooks inside a hook */
callstatus(L->func) |= CIST_HOOKED;
ci->callstatus |= CIST_HOOKED;
lua_unlock(L);
(*hook)(L, &ar);
lua_lock(L);
lua_assert(!L->allowhook);
L->allowhook = 1;
L->func->stkci.framesize = origframesize;
ci->top = restorestack(L, ci_top);
L->top = restorestack(L, top);
callstatus(L->func) &= ~CIST_HOOKED;
ci->callstatus &= ~CIST_HOOKED;
}
}
static void callhook (lua_State *L) {
static void callhook (lua_State *L, CallInfo *ci) {
int hook = LUA_HOOKCALL;
StkId func = L->func;
StkId previous = func - L->func->stkci.previous;
func->stkci.u.l.savedpc++; /* hooks assume 'pc' is already incremented */
if (isLua(previous) &&
GET_OPCODE(*(previous->stkci.u.l.savedpc - 1)) == OP_TAILCALL) {
callstatus(L->func) |= CIST_TAIL;
ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */
if (isLua(ci->previous) &&
GET_OPCODE(*(ci->previous->u.l.savedpc - 1)) == OP_TAILCALL) {
ci->callstatus |= CIST_TAIL;
hook = LUA_HOOKTAILCALL;
}
luaD_hook(L, hook, -1);
func = L->func; /* previous call can change stack */
func->stkci.u.l.savedpc--; /* correct 'pc' */
ci->u.l.savedpc--; /* correct 'pc' */
}
@@ -355,25 +356,28 @@ static int moveresults (lua_State *L, StkId firstResult, StkId res,
** moves current number of results to proper place; returns 0 iff call
** wanted multiple (variable number of) results.
*/
int luaD_poscall (lua_State *L, StkId firstResult, int nres) {
StkId res = L->func; /* res == final position of 1st result */
int wanted = res->stkci.nresults;
int luaD_poscall (lua_State *L, CallInfo *ci, StkId firstResult, int nres) {
StkId res;
int wanted = ci->nresults;
if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) {
if (L->hookmask & LUA_MASKRET) {
ptrdiff_t fr = savestack(L, firstResult); /* hook may change stack */
luaD_hook(L, LUA_HOOKRET, -1);
firstResult = restorestack(L, fr);
res = L->func;
}
/* 'oldpc' for caller function */
L->oldpc = (res - res->stkci.previous)->stkci.u.l.savedpc;
L->oldpc = ci->previous->u.l.savedpc; /* 'oldpc' for caller function */
}
L->func = res - res->stkci.previous;
res = ci->func; /* res == final position of 1st result */
L->ci = ci->previous; /* back to caller */
/* move results to proper place */
return moveresults(L, firstResult, res, nres, wanted);
}
#define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L)))
/*
** Prepares a function call: checks the stack, creates a new CallInfo
** entry, fills in the relevant information, calls hook if needed.
@@ -384,6 +388,7 @@ int luaD_poscall (lua_State *L, StkId firstResult, int nres) {
int luaD_precall (lua_State *L, StkId func, int nresults) {
lua_CFunction f;
TValue *funcv = s2v(func);
CallInfo *ci;
switch (ttype(funcv)) {
case LUA_TCCL: /* C closure */
f = clCvalue(funcv)->f;
@@ -393,19 +398,19 @@ int luaD_precall (lua_State *L, StkId func, int nresults) {
Cfunc: {
int n; /* number of returns */
checkstackp(L, LUA_MINSTACK, func); /* ensure minimum stack size */
func->stkci.nresults = nresults;
func->stkci.previous = func - L->func;
L->func = func;
setfunctop(func, L->top + LUA_MINSTACK);
lua_assert(functop(func) <= L->stack_last);
callstatus(func) = 0;
ci = next_ci(L); /* now 'enter' new function */
ci->nresults = nresults;
ci->func = func;
ci->top = L->top + LUA_MINSTACK;
lua_assert(ci->top <= L->stack_last);
ci->callstatus = 0;
if (L->hookmask & LUA_MASKCALL)
luaD_hook(L, LUA_HOOKCALL, -1);
lua_unlock(L);
n = (*f)(L); /* do the actual call */
lua_lock(L);
api_checknelems(L, n);
luaD_poscall(L, L->top - n, n);
luaD_poscall(L, ci, L->top - n, n);
return 1;
}
case LUA_TLCL: { /* Lua function: prepare its call */
@@ -417,16 +422,15 @@ int luaD_precall (lua_State *L, StkId func, int nresults) {
setnilvalue(s2v(L->top++)); /* complete missing arguments */
if (p->is_vararg)
luaT_adjustvarargs(L, p, n);
func->stkci.nresults = nresults;
func->stkci.previous = func - L->func;
func->stkci.framesize = fsize + 1; /* size includes function itself */
L->func = func;
L->top = func + 1 + fsize;
lua_assert(functop(func) <= L->stack_last);
func->stkci.u.l.savedpc = p->code; /* starting point */
callstatus(func) = 0;
ci = next_ci(L); /* now 'enter' new function */
ci->nresults = nresults;
ci->func = func;
L->top = ci->top = func + 1 + fsize;
lua_assert(ci->top <= L->stack_last);
ci->u.l.savedpc = p->code; /* starting point */
ci->callstatus = CIST_LUA;
if (L->hookmask & LUA_MASKCALL)
callhook(L);
callhook(L, ci);
return 0;
}
default: { /* not a function */
@@ -483,25 +487,24 @@ void luaD_callnoyield (lua_State *L, StkId func, int nResults) {
** continuation function.
*/
static void finishCcall (lua_State *L, int status) {
StkId func = L->func;
CallInfo *ci = L->ci;
int n;
/* must have a continuation and must be able to call it */
lua_assert(func->stkci.u.c.k != NULL && L->nny == 0);
lua_assert(ci->u.c.k != NULL && L->nny == 0);
/* error status can only happen in a protected call */
lua_assert((callstatus(func) & CIST_YPCALL) || status == LUA_YIELD);
if (callstatus(func) & CIST_YPCALL) { /* was inside a pcall? */
callstatus(func) &= ~CIST_YPCALL; /* continuation is also inside it */
L->errfunc = func->stkci.u.c.old_errfunc; /* with same error function */
lua_assert((ci->callstatus & CIST_YPCALL) || status == LUA_YIELD);
if (ci->callstatus & CIST_YPCALL) { /* was inside a pcall? */
ci->callstatus &= ~CIST_YPCALL; /* continuation is also inside it */
L->errfunc = ci->u.c.old_errfunc; /* with the same error function */
}
/* finish 'lua_callk'/'lua_pcall'; CIST_YPCALL and 'errfunc' already
handled */
adjustresults(L, func->stkci.nresults);
adjustresults(L, ci->nresults);
lua_unlock(L);
/* call continuation function */
n = (*func->stkci.u.c.k)(L, status, func->stkci.u.c.ctx);
n = (*ci->u.c.k)(L, status, ci->u.c.ctx); /* call continuation function */
lua_lock(L);
api_checknelems(L, n);
luaD_poscall(L, L->top - n, n); /* finish 'luaD_precall' */
luaD_poscall(L, ci, L->top - n, n); /* finish 'luaD_precall' */
}
@@ -516,8 +519,8 @@ static void finishCcall (lua_State *L, int status) {
static void unroll (lua_State *L, void *ud) {
if (ud != NULL) /* error status? */
finishCcall(L, *(int *)ud); /* finish 'lua_pcallk' callee */
while (L->func != L->stack) { /* something in the stack */
if (!isLua(L->func)) /* C function? */
while (L->ci != &L->base_ci) { /* something in the stack */
if (!isLua(L->ci)) /* C function? */
finishCcall(L, LUA_YIELD); /* complete its execution */
else { /* Lua function */
luaV_finishOp(L); /* finish interrupted instruction */
@@ -531,13 +534,11 @@ static void unroll (lua_State *L, void *ud) {
** Try to find a suspended protected call (a "recover point") for the
** given thread.
*/
static StkId findpcall (lua_State *L) {
StkId func;
for (func = L->func;
func->stkci.previous != 0;
func -= func->stkci.previous) {
if (callstatus(func) & CIST_YPCALL)
return func;
static CallInfo *findpcall (lua_State *L) {
CallInfo *ci;
for (ci = L->ci; ci != NULL; ci = ci->previous) { /* search for a pcall */
if (ci->callstatus & CIST_YPCALL)
return ci;
}
return NULL; /* no pending pcall */
}
@@ -550,17 +551,17 @@ static StkId findpcall (lua_State *L) {
*/
static int recover (lua_State *L, int status) {
StkId oldtop;
StkId recf = findpcall(L);
if (recf == NULL) return 0; /* no recovery point */
CallInfo *ci = findpcall(L);
if (ci == NULL) return 0; /* no recovery point */
/* "finish" luaD_pcall */
oldtop = recf + recf->stkci.u2.funcidx;
oldtop = restorestack(L, ci->u2.funcidx);
luaF_close(L, oldtop);
seterrorobj(L, status, oldtop);
L->func = recf;
L->allowhook = getoah(callstatus(recf)); /* restore original 'allowhook' */
L->ci = ci;
L->allowhook = getoah(ci->callstatus); /* restore original 'allowhook' */
L->nny = 0; /* should be zero to be yieldable */
luaD_shrinkstack(L);
L->errfunc = recf->stkci.u.c.old_errfunc;
L->errfunc = ci->u.c.old_errfunc;
return 1; /* continue running the coroutine */
}
@@ -589,7 +590,7 @@ static int resume_error (lua_State *L, const char *msg, int narg) {
static void resume (lua_State *L, void *ud) {
int n = *(cast(int*, ud)); /* number of arguments */
StkId firstArg = L->top - n; /* first argument */
StkId func = L->func;
CallInfo *ci = L->ci;
if (L->status == LUA_OK) { /* starting a coroutine? */
if (!luaD_precall(L, firstArg - 1, LUA_MULTRET)) /* Lua function? */
luaV_execute(L); /* call it */
@@ -597,18 +598,17 @@ static void resume (lua_State *L, void *ud) {
else { /* resuming from previous yield */
lua_assert(L->status == LUA_YIELD);
L->status = LUA_OK; /* mark that it is running (again) */
if (isLua(func)) /* yielded inside a hook? */
if (isLua(ci)) /* yielded inside a hook? */
luaV_execute(L); /* just continue running Lua code */
else { /* 'common' yield */
if (func->stkci.u.c.k != NULL) { /* does it have a continuation? */
if (ci->u.c.k != NULL) { /* does it have a continuation function? */
lua_unlock(L);
/* call continuation */
n = (*func->stkci.u.c.k)(L, LUA_YIELD, func->stkci.u.c.ctx);
n = (*ci->u.c.k)(L, LUA_YIELD, ci->u.c.ctx); /* call continuation */
lua_lock(L);
api_checknelems(L, n);
firstArg = L->top - n; /* yield results come from continuation */
}
luaD_poscall(L, firstArg, n); /* finish 'luaD_precall' */
luaD_poscall(L, ci, firstArg, n); /* finish 'luaD_precall' */
}
unroll(L, NULL); /* run continuation */
}
@@ -621,7 +621,7 @@ LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs,
unsigned short oldnny = L->nny; /* save "number of non-yieldable" calls */
lua_lock(L);
if (L->status == LUA_OK) { /* may be starting a coroutine */
if (L->func != L->stack) /* not in base level? */
if (L->ci != &L->base_ci) /* not in base level? */
return resume_error(L, "cannot resume non-suspended coroutine", nargs);
}
else if (L->status != LUA_YIELD)
@@ -643,12 +643,12 @@ LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs,
if (errorstatus(status)) { /* unrecoverable error? */
L->status = cast_byte(status); /* mark thread as 'dead' */
seterrorobj(L, status, L->top); /* push error message */
L->func->stkci.framesize = L->top - L->func;
L->ci->top = L->top;
}
else lua_assert(status == L->status); /* normal end or yield */
}
*nresults = (status == LUA_YIELD) ? L->func->stkci.u2.nyield
: L->top - (L->func + 1);
*nresults = (status == LUA_YIELD) ? L->ci->u2.nyield
: L->top - (L->ci->func + 1);
L->nny = oldnny; /* restore 'nny' */
L->nCcalls--;
lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0));
@@ -664,7 +664,7 @@ LUA_API int lua_isyieldable (lua_State *L) {
LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
lua_KFunction k) {
StkId func = L->func;
CallInfo *ci = L->ci;
luai_userstateyield(L, nresults);
lua_lock(L);
api_checknelems(L, nresults);
@@ -675,17 +675,17 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
luaG_runerror(L, "attempt to yield from outside a coroutine");
}
L->status = LUA_YIELD;
if (isLua(func)) { /* inside a hook? */
if (isLua(ci)) { /* inside a hook? */
api_check(L, k == NULL, "hooks cannot continue after yielding");
func->stkci.u2.nyield = 0; /* no results */
ci->u2.nyield = 0; /* no results */
}
else {
if ((func->stkci.u.c.k = k) != NULL) /* is there a continuation? */
func->stkci.u.c.ctx = ctx; /* save context */
func->stkci.u2.nyield = nresults; /* save number of results */
if ((ci->u.c.k = k) != NULL) /* is there a continuation? */
ci->u.c.ctx = ctx; /* save context */
ci->u2.nyield = nresults; /* save number of results */
luaD_throw(L, LUA_YIELD);
}
lua_assert(callstatus(func) & CIST_HOOKED); /* must be inside a hook */
lua_assert(ci->callstatus & CIST_HOOKED); /* must be inside a hook */
lua_unlock(L);
return 0; /* return to 'luaD_hook' */
}
@@ -694,7 +694,7 @@ LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx,
int luaD_pcall (lua_State *L, Pfunc func, void *u,
ptrdiff_t old_top, ptrdiff_t ef) {
int status;
ptrdiff_t oldfunc = savestack(L, L->func);
CallInfo *old_ci = L->ci;
lu_byte old_allowhooks = L->allowhook;
unsigned short old_nny = L->nny;
ptrdiff_t old_errfunc = L->errfunc;
@@ -704,7 +704,7 @@ int luaD_pcall (lua_State *L, Pfunc func, void *u,
StkId oldtop = restorestack(L, old_top);
luaF_close(L, oldtop); /* close possible pending closures */
seterrorobj(L, status, oldtop);
L->func = restorestack(L, oldfunc);
L->ci = old_ci;
L->allowhook = old_allowhooks;
L->nny = old_nny;
luaD_shrinkstack(L);