commit 0e45ffb8e41fa8f6b156bdaff0685e1ddfdfbd2a
parent 071e54ae0b2fb79bc38c2ca95354886b827c7ccb
Author: Roberto Ierusalimschy <roberto@inf.puc-rio.br>
Date: Mon, 14 Sep 2009 11:30:15 -0300
first implementation of 'lua_yieldk' (yield with continuation)
Diffstat:
3 files changed, 39 insertions(+), 9 deletions(-)
diff --git a/ldo.c b/ldo.c
@@ -1,5 +1,5 @@
/*
-** $Id: ldo.c,v 2.65 2009/06/01 19:09:26 roberto Exp roberto $
+** $Id: ldo.c,v 2.66 2009/07/15 17:26:14 roberto Exp roberto $
** Stack and Call structure of Lua
** See Copyright Notice in lua.h
*/
@@ -418,6 +418,16 @@ static void resume (lua_State *L, void *ud) {
if (isLua(ci)) /* yielded inside a hook? */
luaV_execute(L);
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);
+ firstArg = L->top - n;
+ }
G(L)->nCcalls--; /* finish 'luaD_call' */
luaD_poscall(L, firstArg); /* finish 'luaD_precall' */
}
@@ -499,17 +509,25 @@ LUA_API int lua_resume (lua_State *L, int nargs) {
return status;
}
-LUA_API int lua_yield (lua_State *L, int nresults) {
+LUA_API int lua_yieldk (lua_State *L, int nresults, int ctx, lua_CFunction k) {
+ CallInfo *ci = L->ci;
luai_userstateyield(L, nresults);
lua_lock(L);
if (L->nny > 0)
luaG_runerror(L, "attempt to yield across metamethod/C-call boundary");
L->status = LUA_YIELD;
- if (!isLua(L->ci)) { /* not inside a hook? */
- L->ci->func = L->top - nresults - 1; /* protect stack slots below ??? */
+ if (isLua(ci)) { /* inside a hook? */
+ api_check(L, k == NULL, "hooks cannot continue after yielding");
+ }
+ else {
+ if ((ci->u.c.k = k) != NULL) { /* is there a continuation? */
+ ci->u.c.ctx = ctx; /* save context */
+ ci->u.c.oldtop = savestack(L, ci->func); /* save current 'func' */
+ }
+ ci->func = L->top - nresults - 1; /* protect stack slots below */
luaD_throw(L, LUA_YIELD);
}
- lua_assert(L->ci->callstatus & CIST_HOOKED); /* must be inside a hook */
+ lua_assert(ci->callstatus & CIST_HOOKED); /* must be inside a hook */
lua_unlock(L);
return 0; /* otherwise, return to 'luaD_callhook' */
}
diff --git a/ltests.c b/ltests.c
@@ -1,5 +1,5 @@
/*
-** $Id: ltests.c,v 2.69 2009/08/26 17:41:26 roberto Exp roberto $
+** $Id: ltests.c,v 2.70 2009/09/09 20:44:10 roberto Exp roberto $
** Internal Module for Debugging of the Lua Implementation
** See Copyright Notice in lua.h
*/
@@ -836,6 +836,8 @@ static int getnum_aux (lua_State *L, const char **pc) {
sig = -1;
(*pc)++;
}
+ if (!lisdigit(cast(unsigned char, **pc)))
+ luaL_error(L, "number expected (%s)", *pc);
while (lisdigit(cast(unsigned char, **pc))) res = res*10 + (*(*pc)++) - '0';
return sig*res;
}
@@ -1033,6 +1035,11 @@ static int runC (lua_State *L, lua_State *L1, const char *pc) {
else if EQ("yield") {
return lua_yield(L1, getnum);
}
+ else if EQ("yieldk") {
+ int nres = getnum;
+ int i = getnum;
+ return lua_yieldk(L1, nres, i, Cfunck);
+ }
else if EQ("loadstring") {
size_t sl;
const char *s = luaL_checklstring(L1, getnum, &sl);
@@ -1056,9 +1063,12 @@ static int runC (lua_State *L, lua_State *L1, const char *pc) {
lua_pushinteger(L1, lua_objlen(L1, i));
}
else if EQ("getctx") {
+ static const char *const codes[] = {"OK", "YIELD", "ERRRUN",
+ "ERRSYNTAX", "ERRMEM", "ERRGCMM", "ERRERR"};
+
int i = 0;
int s = lua_getctx(L1, &i);
- lua_pushinteger(L1, s);
+ lua_pushstring(L1, codes[s]);
lua_pushinteger(L1, i);
}
else if EQ("checkstack") {
diff --git a/lua.h b/lua.h
@@ -1,5 +1,5 @@
/*
-** $Id: lua.h,v 1.240 2009/06/18 18:59:18 roberto Exp roberto $
+** $Id: lua.h,v 1.241 2009/07/15 17:26:14 roberto Exp roberto $
** Lua - An Extensible Extension Language
** Lua.org, PUC-Rio, Brazil (http://www.lua.org)
** See Copyright Notice at the end of this file
@@ -243,7 +243,9 @@ LUA_API int (lua_dump) (lua_State *L, lua_Writer writer, void *data);
/*
** coroutine functions
*/
-LUA_API int (lua_yield) (lua_State *L, int nresults);
+LUA_API int (lua_yieldk) (lua_State *L, int nresults, int ctx,
+ lua_CFunction k);
+#define lua_yield(L,n) lua_yieldk(L, (n), 0, NULL)
LUA_API int (lua_resume) (lua_State *L, int narg);
LUA_API int (lua_status) (lua_State *L);