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reordering of some functions + cleaner way to code lua_resume/resume +

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small bug in lua_resume (in case of calling errors lua_resume should
remove only new arguments from the stack and push error message).
This commit is contained in:
Roberto Ierusalimschy 2009-12-10 16:20:07 -02:00
parent 64d5df7772
commit 2bb19ccf08
1 changed files with 60 additions and 60 deletions
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120
ldo.c
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@ -1,5 +1,5 @@
/* /*
** $Id: ldo.c,v 2.74 2009/11/27 15:37:59 roberto Exp roberto $ ** $Id: ldo.c,v 2.75 2009/12/08 18:59:24 roberto Exp roberto $
** Stack and Call structure of Lua ** Stack and Call structure of Lua
** See Copyright Notice in lua.h ** See Copyright Notice in lua.h
*/ */
@ -59,9 +59,7 @@ void luaD_seterrorobj (lua_State *L, int errcode, StkId oldtop) {
setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling")); setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling"));
break; break;
} }
case LUA_ERRSYNTAX: default: {
case LUA_ERRGCMM:
case LUA_ERRRUN: {
setobjs2s(L, oldtop, L->top - 1); /* error message on current top */ setobjs2s(L, oldtop, L->top - 1); /* error message on current top */
break; break;
} }
@ -404,58 +402,6 @@ static void unroll (lua_State *L, void *ud) {
} }
/*
** data to be passed to 'resume' by 'lua_resume'
*/
struct ResumeData {
StkId firstArg; /* stack index of first argument */
int recover; /* should try to recover in case of errors */
};
/*
** do the work for 'lua_resume' in protected mode
*/
static void resume (lua_State *L, void *ud) {
struct ResumeData *rd = cast(struct ResumeData *, ud);
CallInfo *ci = L->ci;
if (G(L)->nCcalls >= LUAI_MAXCCALLS)
luaG_runerror(L, "C stack overflow");
if (L->status == LUA_OK) { /* may be starting a coroutine */
if (ci != &L->base_ci) { /* not in base level? */
rd->recover = 0; /* thread may not be running as a coroutine */
luaG_runerror(L, "cannot resume non-suspended coroutine");
}
/* coroutine is in base level; start running it */
if (!luaD_precall(L, rd->firstArg - 1, LUA_MULTRET)) /* Lua function? */
luaV_execute(L); /* call it */
}
else if (L->status != LUA_YIELD)
luaG_runerror(L, "cannot resume dead coroutine");
else { /* resuming from previous yield */
L->status = LUA_OK;
if (isLua(ci)) /* yielded inside a hook? */
luaV_execute(L); /* just continue running Lua code */
else { /* 'common' yield */
if (ci->u.c.k != NULL) { /* does it have a continuation? */
int n;
ci->u.c.status = LUA_YIELD; /* 'default' status */
ci->callstatus |= CIST_YIELDED;
ci->func = restorestack(L, ci->u.c.oldtop);
lua_unlock(L);
n = (*ci->u.c.k)(L); /* call continuation */
lua_lock(L);
api_checknelems(L, n);
rd->firstArg = L->top - n; /* yield results come from continuation */
}
G(L)->nCcalls--; /* finish 'luaD_call' */
luaD_poscall(L, rd->firstArg); /* finish 'luaD_precall' */
}
unroll(L, NULL);
}
}
/* /*
** check whether thread has a suspended protected call ** check whether thread has a suspended protected call
*/ */
@ -488,16 +434,70 @@ static int recover (lua_State *L, int status) {
} }
/*
** signal an error in the call to 'resume', not in the execution of the
** coroutine itself. (Such errors should not be handled by any coroutine
** error hanlder and should not kill the coroutine.)
*/
static void resume_error (lua_State *L, const char *msg, StkId firstArg) {
L->top = firstArg; /* remove args from the stack */
setsvalue2s(L, L->top, luaS_new(L, msg)); /* push error message */
incr_top(L);
luaD_throw(L, -1); /* jump back to 'lua_resume' */
}
/*
** do the work for 'lua_resume' in protected mode
*/
static void resume (lua_State *L, void *ud) {
StkId firstArg = cast(StkId, ud);
CallInfo *ci = L->ci;
if (G(L)->nCcalls >= LUAI_MAXCCALLS)
resume_error(L, "C stack overflow", firstArg);
if (L->status == LUA_OK) { /* may be starting a coroutine */
if (ci != &L->base_ci) /* not in base level? */
resume_error(L, "cannot resume non-suspended coroutine", firstArg);
/* coroutine is in base level; start running it */
if (!luaD_precall(L, firstArg - 1, LUA_MULTRET)) /* Lua function? */
luaV_execute(L); /* call it */
}
else if (L->status != LUA_YIELD)
resume_error(L, "cannot resume dead coroutine", firstArg);
else { /* resuming from previous yield */
L->status = LUA_OK;
if (isLua(ci)) /* yielded inside a hook? */
luaV_execute(L); /* just continue running Lua code */
else { /* 'common' yield */
if (ci->u.c.k != NULL) { /* does it have a continuation? */
int n;
ci->u.c.status = LUA_YIELD; /* 'default' status */
ci->callstatus |= CIST_YIELDED;
ci->func = restorestack(L, ci->u.c.oldtop);
lua_unlock(L);
n = (*ci->u.c.k)(L); /* call continuation */
lua_lock(L);
api_checknelems(L, n);
firstArg = L->top - n; /* yield results come from continuation */
}
G(L)->nCcalls--; /* finish 'luaD_call' */
luaD_poscall(L, firstArg); /* finish 'luaD_precall' */
}
unroll(L, NULL);
}
}
LUA_API int lua_resume (lua_State *L, int nargs) { LUA_API int lua_resume (lua_State *L, int nargs) {
struct ResumeData rd;
int status; int status;
lua_lock(L); lua_lock(L);
luai_userstateresume(L, nargs); luai_userstateresume(L, nargs);
++G(L)->nCcalls; /* count resume */ ++G(L)->nCcalls; /* count resume */
L->nny = 0; /* allow yields */ L->nny = 0; /* allow yields */
rd.firstArg = L->top - nargs; rd.recover = 1; status = luaD_rawrunprotected(L, resume, L->top - nargs);
status = luaD_rawrunprotected(L, resume, &rd); if (status == -1) /* error calling 'lua_resume'? */
if (rd.recover) { status = LUA_ERRRUN;
else { /* yield or regular error */
while (status != LUA_OK && status != LUA_YIELD) { /* error? */ while (status != LUA_OK && status != LUA_YIELD) { /* error? */
if (recover(L, status)) /* recover point? */ if (recover(L, status)) /* recover point? */
status = luaD_rawrunprotected(L, unroll, NULL); /* run continuation */ status = luaD_rawrunprotected(L, unroll, NULL); /* run continuation */