commit ba36180fd7b68341ad57e0fbe7a55cdfb334908d
parent b9e76be8a691ed83a716a85c6b85cb80f66cc480
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Thu, 2 Nov 2017 09:28:29 -0200
new API for 'lua_resume' + cleaning the uses of the 'extra' field in
'CallInfo'
Diffstat:
7 files changed, 31 insertions(+), 58 deletions(-)
diff --git a/lapi.c b/lapi.c
@@ -1,5 +1,5 @@
/*
-** $Id: lapi.c,v 2.271 2017/10/11 12:38:45 roberto Exp roberto $
+** $Id: lapi.c,v 2.272 2017/11/01 18:20:48 roberto Exp roberto $
** Lua API
** See Copyright Notice in lua.h
*/
@@ -58,10 +58,9 @@ const char lua_ident[] =
static TValue *index2value (lua_State *L, int idx) {
- CallInfo *ci = L->ci;
if (idx > 0) {
StkId o = L->func + idx;
- api_check(L, idx <= ci->top - (L->func + 1), "unacceptable index");
+ api_check(L, idx <= L->ci->top - (L->func + 1), "unacceptable index");
if (o >= L->top) return NONVALIDVALUE;
else return s2v(o);
}
@@ -1000,7 +999,7 @@ LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc,
ci->u.c.k = k; /* save continuation */
ci->u.c.ctx = ctx; /* save context */
/* save information for error recovery */
- ci->extra = savestack(L, c.func);
+ ci->u2.funcidx = savestack(L, c.func);
ci->u.c.old_errfunc = L->errfunc;
L->errfunc = func;
setoah(ci->callstatus, L->allowhook); /* save value of 'allowhook' */
diff --git a/lcorolib.c b/lcorolib.c
@@ -1,5 +1,5 @@
/*
-** $Id: lcorolib.c,v 1.9 2014/11/02 19:19:04 roberto Exp roberto $
+** $Id: lcorolib.c,v 1.10 2016/04/11 19:19:55 roberto Exp roberto $
** Coroutine Library
** See Copyright Notice in lua.h
*/
@@ -26,7 +26,7 @@ static lua_State *getco (lua_State *L) {
static int auxresume (lua_State *L, lua_State *co, int narg) {
- int status;
+ int status, nres;
if (!lua_checkstack(co, narg)) {
lua_pushliteral(L, "too many arguments to resume");
return -1; /* error flag */
@@ -36,9 +36,8 @@ static int auxresume (lua_State *L, lua_State *co, int narg) {
return -1; /* error flag */
}
lua_xmove(L, co, narg);
- status = lua_resume(co, L, narg);
+ status = lua_resume(co, L, narg, &nres);
if (status == LUA_OK || status == LUA_YIELD) {
- int nres = lua_gettop(co);
if (!lua_checkstack(L, nres + 1)) {
lua_pop(co, nres); /* remove results anyway */
lua_pushliteral(L, "too many results to resume");
diff --git a/ldebug.c b/ldebug.c
@@ -1,5 +1,5 @@
/*
-** $Id: ldebug.c,v 2.133 2017/10/31 17:14:02 roberto Exp roberto $
+** $Id: ldebug.c,v 2.134 2017/11/01 18:20:48 roberto Exp roberto $
** Debug Interface
** See Copyright Notice in lua.h
*/
@@ -107,22 +107,6 @@ static int currentline (CallInfo *ci) {
/*
-** If function yielded, its 'func' can be in the 'extra' field. The
-** next function restores 'func' to its correct value for debugging
-** purposes. (It exchanges 'func' and 'extra'; so, when called again,
-** after debugging, it also "re-restores" ** 'func' to its altered value.
-*/
-static void swapextra (lua_State *L) {
- if (L->status == LUA_YIELD) {
- CallInfo *ci = L->ci; /* get function that yielded */
- StkId temp = ci->func; /* exchange its 'func' and 'extra' values */
- L->func = ci->func = restorestack(L, ci->extra);
- ci->extra = savestack(L, temp);
- }
-}
-
-
-/*
** This function can be called asynchronously (e.g. during a signal).
** Fields 'oldpc', 'basehookcount', and 'hookcount' (set by
** 'resethookcount') are for debug only, and it is no problem if they
@@ -209,7 +193,6 @@ static const char *findlocal (lua_State *L, CallInfo *ci, int n,
LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
const char *name;
lua_lock(L);
- swapextra(L);
if (ar == NULL) { /* information about non-active function? */
if (!isLfunction(s2v(L->top - 1))) /* not a Lua function? */
name = NULL;
@@ -224,7 +207,6 @@ LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) {
api_incr_top(L);
}
}
- swapextra(L);
lua_unlock(L);
return name;
}
@@ -234,13 +216,11 @@ LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) {
StkId pos = NULL; /* to avoid warnings */
const char *name;
lua_lock(L);
- swapextra(L);
name = findlocal(L, ar->i_ci, n, &pos);
if (name) {
setobjs2s(L, pos, L->top - 1);
L->top--; /* pop value */
}
- swapextra(L);
lua_unlock(L);
return name;
}
@@ -361,7 +341,6 @@ LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
CallInfo *ci;
TValue *func;
lua_lock(L);
- swapextra(L);
if (*what == '>') {
ci = NULL;
func = s2v(L->top - 1);
@@ -380,7 +359,6 @@ LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) {
setobj2s(L, L->top, func);
api_incr_top(L);
}
- swapextra(L); /* correct before option 'L', which can raise a mem. error */
if (strchr(what, 'L'))
collectvalidlines(L, cl);
lua_unlock(L);
@@ -790,7 +768,6 @@ void luaG_traceexec (lua_State *L) {
L->hookcount = 1; /* undo decrement to zero */
ci->u.l.savedpc--; /* undo increment (resume will increment it again) */
ci->callstatus |= CIST_HOOKYIELD; /* mark that it yielded */
- L->func = ci->func = L->top - 1; /* protect stack below results */
luaD_throw(L, LUA_YIELD);
}
}
diff --git a/ldo.c b/ldo.c
@@ -1,5 +1,5 @@
/*
-** $Id: ldo.c,v 2.163 2017/10/31 17:54:35 roberto Exp roberto $
+** $Id: ldo.c,v 2.164 2017/11/01 18:20:48 roberto Exp roberto $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@@ -559,7 +559,7 @@ static int recover (lua_State *L, int status) {
CallInfo *ci = findpcall(L);
if (ci == NULL) return 0; /* no recovery point */
/* "finish" luaD_pcall */
- oldtop = restorestack(L, ci->extra);
+ oldtop = restorestack(L, ci->u2.funcidx);
luaF_close(L, oldtop);
seterrorobj(L, status, oldtop);
L->ci = ci;
@@ -604,7 +604,6 @@ 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) */
- L->func = ci->func = restorestack(L, ci->extra);
if (isLua(ci)) /* yielded inside a hook? */
luaV_execute(L); /* just continue running Lua code */
else { /* 'common' yield */
@@ -622,7 +621,8 @@ static void resume (lua_State *L, void *ud) {
}
-LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) {
+LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs,
+ int *nresults) {
int status;
unsigned short oldnny = L->nny; /* save "number of non-yieldable" calls */
lua_lock(L);
@@ -653,6 +653,8 @@ LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) {
}
else lua_assert(status == L->status); /* normal end or yield */
}
+ *nresults = (status == LUA_YIELD) ? L->ci->u2.nyield
+ : L->top - (L->func + 1);
L->nny = oldnny; /* restore 'nny' */
L->nCcalls--;
lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0));
@@ -679,14 +681,14 @@ 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;
- ci->extra = savestack(L, L->func); /* save current 'func' */
if (isLua(ci)) { /* inside a hook? */
api_check(L, k == NULL, "hooks cannot continue after yielding");
+ ci->u2.nyield = 0; /* no results */
}
else {
if ((ci->u.c.k = k) != NULL) /* is there a continuation? */
ci->u.c.ctx = ctx; /* save context */
- L->func = ci->func = L->top - nresults - 1; /* protect stack below results */
+ ci->u2.nyield = nresults; /* save number of results */
luaD_throw(L, LUA_YIELD);
}
lua_assert(ci->callstatus & CIST_HOOKED); /* must be inside a hook */
diff --git a/lstate.h b/lstate.h
@@ -1,5 +1,5 @@
/*
-** $Id: lstate.h,v 2.144 2017/07/27 13:50:16 roberto Exp roberto $
+** $Id: lstate.h,v 2.145 2017/10/31 17:54:35 roberto Exp roberto $
** Global State
** See Copyright Notice in lua.h
*/
@@ -83,12 +83,6 @@ typedef struct stringtable {
/*
** Information about a call.
-** When a thread yields, 'func' is adjusted to pretend that the
-** top function has only the yielded values in its stack; in that
-** case, the actual 'func' value is saved in field 'extra'.
-** When a function calls another with a continuation, 'extra' keeps
-** the function index so that, in case of errors, the continuation
-** function can be called with the correct top.
*/
typedef struct CallInfo {
StkId func; /* function index in the stack */
@@ -104,7 +98,10 @@ typedef struct CallInfo {
lua_KContext ctx; /* context info. in case of yields */
} c;
} u;
- ptrdiff_t extra;
+ union {
+ ptrdiff_t funcidx; /* called-function index */
+ int nyield; /* number of values yielded */
+ } u2;
short nresults; /* expected number of results from this function */
unsigned short callstatus;
} CallInfo;
diff --git a/ltests.c b/ltests.c
@@ -1,5 +1,5 @@
/*
-** $Id: ltests.c,v 2.225 2017/10/04 21:56:32 roberto Exp roberto $
+** $Id: ltests.c,v 2.226 2017/11/01 18:20:48 roberto Exp roberto $
** Internal Module for Debugging of the Lua Implementation
** See Copyright Notice in lua.h
*/
@@ -309,13 +309,10 @@ static void checkLclosure (global_State *g, LClosure *cl) {
}
-static int lua_checkpc (lua_State *L, CallInfo *ci) {
+static int lua_checkpc (CallInfo *ci) {
if (!isLua(ci)) return 1;
else {
- /* if function yielded (inside a hook), real 'func' is in 'extra' field */
- StkId f = (L->status != LUA_YIELD || ci != L->ci)
- ? ci->func
- : restorestack(L, ci->extra);
+ StkId f = ci->func;
Proto *p = clLvalue(s2v(f))->p;
return p->code <= ci->u.l.savedpc &&
ci->u.l.savedpc <= p->code + p->sizecode;
@@ -332,7 +329,7 @@ static void checkstack (global_State *g, lua_State *L1) {
lua_assert(upisopen(uv)); /* must be open */
for (ci = L1->ci; ci != NULL; ci = ci->previous) {
lua_assert(ci->top <= L1->stack_last);
- lua_assert(lua_checkpc(L1, ci));
+ lua_assert(lua_checkpc(ci));
}
if (L1->stack) { /* complete thread? */
for (o = L1->stack; o < L1->stack_last + EXTRA_STACK; o++)
@@ -1411,7 +1408,8 @@ static int runC (lua_State *L, lua_State *L1, const char *pc) {
}
else if EQ("resume") {
int i = getindex;
- status = lua_resume(lua_tothread(L1, i), L, getnum);
+ int nres;
+ status = lua_resume(lua_tothread(L1, i), L, getnum, &nres);
}
else if EQ("return") {
int n = getnum;
@@ -1616,10 +1614,10 @@ static int sethook (lua_State *L) {
static int coresume (lua_State *L) {
- int status;
+ int status, nres;
lua_State *co = lua_tothread(L, 1);
luaL_argcheck(L, co, 1, "coroutine expected");
- status = lua_resume(co, L, 0);
+ status = lua_resume(co, L, 0, &nres);
if (status != LUA_OK && status != LUA_YIELD) {
lua_pushboolean(L, 0);
lua_insert(L, -2);
diff --git a/lua.h b/lua.h
@@ -1,5 +1,5 @@
/*
-** $Id: lua.h,v 1.335 2017/05/26 19:14:29 roberto Exp roberto $
+** $Id: lua.h,v 1.336 2017/07/27 13:36:54 roberto Exp roberto $
** Lua - A Scripting Language
** Lua.org, PUC-Rio, Brazil (http://www.lua.org)
** See Copyright Notice at the end of this file
@@ -288,7 +288,8 @@ LUA_API int (lua_dump) (lua_State *L, lua_Writer writer, void *data, int strip);
*/
LUA_API int (lua_yieldk) (lua_State *L, int nresults, lua_KContext ctx,
lua_KFunction k);
-LUA_API int (lua_resume) (lua_State *L, lua_State *from, int narg);
+LUA_API int (lua_resume) (lua_State *L, lua_State *from, int narg,
+ int *nres);
LUA_API int (lua_status) (lua_State *L);
LUA_API int (lua_isyieldable) (lua_State *L);
