support for yield inside hooks

This commit is contained in:
Roberto Ierusalimschy 2002-11-18 13:24:11 -02:00
parent c4ae00a3d1
commit 9bab2cf55d
2 changed files with 35 additions and 22 deletions

44
ldo.c
View File

@ -1,5 +1,5 @@
/*
** $Id: ldo.c,v 1.201 2002/11/14 16:15:53 roberto Exp roberto $
** $Id: ldo.c,v 1.202 2002/11/18 11:01:55 roberto Exp roberto $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@ -308,15 +308,20 @@ static void resume (lua_State *L, void *ud) {
luaG_runerror(L, "cannot resume dead coroutine");
luaD_precall(L, L->top - (nargs + 1)); /* start coroutine */
}
else if (ci->state && CI_YIELD) { /* inside a yield? */
/* finish interrupted execution of `OP_CALL' */
int nresults;
lua_assert((ci-1)->state & CI_SAVEDPC);
lua_assert(GET_OPCODE(*((ci-1)->u.l.savedpc - 1)) == OP_CALL ||
GET_OPCODE(*((ci-1)->u.l.savedpc - 1)) == OP_TAILCALL);
nresults = GETARG_C(*((ci-1)->u.l.savedpc - 1)) - 1;
luaD_poscall(L, nresults, L->top - nargs); /* complete it */
if (nresults >= 0) L->top = L->ci->top;
else if (ci->state & CI_YIELD) { /* inside a yield? */
if (ci->state & CI_C) { /* `common' yield? */
/* finish interrupted execution of `OP_CALL' */
int nresults;
lua_assert((ci-1)->state & CI_SAVEDPC);
lua_assert(GET_OPCODE(*((ci-1)->u.l.savedpc - 1)) == OP_CALL ||
GET_OPCODE(*((ci-1)->u.l.savedpc - 1)) == OP_TAILCALL);
nresults = GETARG_C(*((ci-1)->u.l.savedpc - 1)) - 1;
luaD_poscall(L, nresults, L->top - nargs); /* complete it */
if (nresults >= 0) L->top = L->ci->top;
}
else { /* yielded inside a hook: just continue its execution */
ci->state &= ~CI_YIELD;
}
}
else
luaG_runerror(L, "cannot resume non-suspended coroutine");
@ -349,15 +354,18 @@ LUA_API int lua_yield (lua_State *L, int nresults) {
CallInfo *ci;
lua_lock(L);
ci = L->ci;
if ((ci-1)->state & CI_C)
luaG_runerror(L, "cannot yield a C function");
lua_assert(ci->state & CI_C); /* current function is not Lua */
if (L->top - nresults > ci->base) { /* is there garbage in the stack? */
int i;
for (i=0; i<nresults; i++) /* move down results */
setobjs2s(ci->base + i, L->top - nresults + i);
L->top = ci->base + nresults;
if (ci->state & CI_C) { /* usual yield */
if ((ci-1)->state & CI_C)
luaG_runerror(L, "cannot yield a C function");
if (L->top - nresults > ci->base) { /* is there garbage in the stack? */
int i;
for (i=0; i<nresults; i++) /* move down results */
setobjs2s(ci->base + i, L->top - nresults + i);
L->top = ci->base + nresults;
}
}
/* else it's an yield inside a hook: nothing to do */
ci->state |= CI_YIELD;
lua_unlock(L);
return -1;
}

13
lvm.c
View File

@ -1,5 +1,5 @@
/*
** $Id: lvm.c,v 1.261 2002/11/14 16:15:53 roberto Exp roberto $
** $Id: lvm.c,v 1.262 2002/11/18 11:01:55 roberto Exp roberto $
** Lua virtual machine
** See Copyright Notice in lua.h
*/
@ -393,8 +393,14 @@ StkId luaV_execute (lua_State *L) {
const Instruction i = *pc++;
StkId ra;
if (L->hookmask >= LUA_MASKLINE &&
(--L->hookcount == 0 || L->hookmask & LUA_MASKLINE))
(--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
traceexec(L);
if (L->ci->state & CI_YIELD) { /* did hook yield? */
L->ci->u.l.savedpc = pc - 1;
L->ci->state |= CI_SAVEDPC;
return NULL;
}
}
/* warning!! several calls may realloc the stack and invalidate `ra' */
ra = RA(i);
lua_assert(L->top <= L->stack + L->stacksize && L->top >= L->ci->base);
@ -595,8 +601,7 @@ StkId luaV_execute (lua_State *L) {
if (firstResult) {
if (firstResult > L->top) { /* yield? */
(L->ci - 1)->u.l.savedpc = pc;
(L->ci - 1)->state = CI_SAVEDPC;
L->ci->state |= CI_YIELD;
(L->ci - 1)->state |= CI_SAVEDPC;
return NULL;
}
/* it was a C function (`precall' called it); adjust results */