'context' added to suspendable calls

lapi.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lapi.c,v 2.70 2009/02/19 17:15:13 roberto Exp roberto $
+** $Id: lapi.c,v 2.71 2009/03/10 17:14:37 roberto Exp roberto $
 ** Lua API
 ** See Copyright Notice in lua.h
 */
@@ -761,17 +761,28 @@ LUA_API int lua_setfenv (lua_State *L, int idx) {
      api_check(L, (nr) == LUA_MULTRET || (L->ci->top - L->top >= (nr) - (na)))
 
 
-LUA_API void lua_callcont (lua_State *L, int nargs, int nresults,
-                           lua_CFunction cont) {
+LUA_API int lua_getctx (lua_State *L, int *ctx) {
+  if (L->ci->callstatus & CIST_CTX) {  /* call has ctx? */
+    *ctx = L->ci->u.c.ctx;
+    return LUA_YIELD;
+  }
+  else return LUA_OK;
+}
+
+
+LUA_API void lua_callk (lua_State *L, int nargs, int nresults, int ctx,
+                        lua_CFunction k) {
   StkId func;
   lua_lock(L);
   /* cannot use continuations inside hooks */
-  api_check(L, cont == NULL || !isLua(L->ci));
+  api_check(L, k == NULL || !isLua(L->ci));
   api_checknelems(L, nargs+1);
   checkresults(L, nargs, nresults);
   func = L->top - (nargs+1);
-  if (cont) {
-    L->ci->u.c.cont = cont;
+  if (k != NULL) {
+    L->ci->u.c.k = k;
+    L->ci->u.c.ctx = ctx;
+    L->ci->callstatus |= CIST_CTX;
     luaD_call(L, func, nresults, 1);
   }
   else

lbaselib.c

@@ -1,5 +1,5 @@
 /*
-** $Id: lbaselib.c,v 1.212 2009/03/13 15:50:03 roberto Exp roberto $
+** $Id: lbaselib.c,v 1.213 2009/03/16 16:30:50 roberto Exp roberto $
 ** Basic library
 ** See Copyright Notice in lua.h
 */
@@ -358,7 +358,7 @@ static int luaB_dofile (lua_State *L) {
   const char *fname = luaL_optstring(L, 1, NULL);
   lua_settop(L, 1);
   if (luaL_loadfile(L, fname) != LUA_OK) lua_error(L);
-  lua_callcont(L, 0, LUA_MULTRET, dofilecont);
+  lua_callk(L, 0, LUA_MULTRET, 0, dofilecont);
   return dofilecont(L);
 }
 

ldo.c

@@ -1,5 +1,5 @@
 /*
-** $Id: ldo.c,v 2.54 2009/03/04 13:32:29 roberto Exp roberto $
+** $Id: ldo.c,v 2.55 2009/03/10 17:14:37 roberto Exp roberto $
 ** Stack and Call structure of Lua
 ** See Copyright Notice in lua.h
 */
@@ -385,7 +385,7 @@ void luaD_call (lua_State *L, StkId func, int nResults, int allowyield) {
 
 static void finishCcall (lua_State *L) {
   int n;
-  lua_assert(L->ci->u.c.cont != NULL);  /* must have a continuation */
+  lua_assert(L->ci->u.c.k != NULL);  /* must have a continuation */
   lua_assert(L->nny == 0);
   /* finish 'luaD_call' */
   G(L)->nCcalls--;
@@ -393,7 +393,7 @@ static void finishCcall (lua_State *L) {
   adjustresults(L, (L->ci + 1)->nresults);
   /* call continuation function */
   lua_unlock(L);
-  n = (*L->ci->u.c.cont)(L);
+  n = (*L->ci->u.c.k)(L);
   lua_lock(L);
   /* finish 'luaD_precall' */
   luaD_poscall(L, L->top - n);
@@ -477,7 +477,6 @@ LUA_API int lua_resume (lua_State *L, int nargs) {
   return status;
 }
 
-
 LUA_API int lua_yield (lua_State *L, int nresults) {
   luai_userstateyield(L, nresults);
   lua_lock(L);

lstate.h

@@ -1,5 +1,5 @@
 /*
-** $Id: lstate.h,v 2.38 2009/03/04 13:32:29 roberto Exp roberto $
+** $Id: lstate.h,v 2.39 2009/03/10 17:14:37 roberto Exp roberto $
 ** Global State
 ** See Copyright Notice in lua.h
 */
@@ -88,7 +88,8 @@ typedef struct CallInfo {
       int tailcalls;  /* number of tail calls lost under this entry */
     } l;
     struct {  /* only for C functions */
-      lua_CFunction cont;  /* continuation in case of yields */
+      int ctx;  /* context info. in case of yields */
+      lua_CFunction k;  /* continuation in case of yields */
     } c;
   } u;
 } CallInfo;
@@ -101,6 +102,7 @@ typedef struct CallInfo {
 #define CIST_HOOKED	2	/* call is running a debug hook */
 #define CIST_REENTRY	4	/* call is running on same invocation of
                                    luaV_execute of previous call */
+#define CIST_CTX	8	/* call has a ctx value */
 
 
 #define curr_func(L)	(clvalue(L->ci->func))

ltablib.c

@@ -1,5 +1,5 @@
 /*
-** $Id: ltablib.c,v 1.44 2008/04/07 18:43:00 roberto Exp roberto $
+** $Id: ltablib.c,v 1.45 2009/03/10 17:14:37 roberto Exp roberto $
 ** Library for Table Manipulation
 ** See Copyright Notice in lua.h
 */
@@ -20,14 +20,16 @@
 
 
 static int foreachi (lua_State *L) {
-  int i;
   int n = aux_getn(L, 1);
+  int i;
+  if (lua_getctx(L, &i) == LUA_YIELD) goto poscall;
   luaL_checktype(L, 2, LUA_TFUNCTION);
-  for (i=1; i <= n; i++) {
+  for (i = 1; i <= n; i++) {
     lua_pushvalue(L, 2);  /* function */
     lua_pushinteger(L, i);  /* 1st argument */
     lua_rawgeti(L, 1, i);  /* 2nd argument */
-    lua_call(L, 2, 1);
+    lua_callk(L, 2, 1, i, foreachi);
+    poscall:
     if (!lua_isnil(L, -1))
       return 1;
     lua_pop(L, 1);  /* remove nil result */
@@ -46,7 +48,7 @@ static int foreachcont (lua_State *L) {
     lua_pushvalue(L, 2);  /* function */
     lua_pushvalue(L, -3);  /* key */
     lua_pushvalue(L, -3);  /* value */
-    lua_callcont(L, 2, 1, &foreachcont);
+    lua_callk(L, 2, 1, 0, foreachcont);
   }
 }
 

lua.h

@@ -1,5 +1,5 @@
 /*
-** $Id: lua.h,v 1.232 2009/02/18 17:20:56 roberto Exp roberto $
+** $Id: lua.h,v 1.233 2009/03/10 17:14:37 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
@@ -203,8 +203,11 @@ LUA_API int   (lua_setfenv) (lua_State *L, int idx);
 /*
 ** 'load' and 'call' functions (load and run Lua code)
 */
-LUA_API void  (lua_callcont) (lua_State *L, int nargs, int nresults,
-                              lua_CFunction cont);
+LUA_API void  (lua_callk) (lua_State *L, int nargs, int nresults, int ctx,
+                           lua_CFunction k);
+#define lua_call(L,n,r)		lua_callk(L, (n), (r), 0, NULL)
+
+LUA_API int   (lua_getctx) (lua_State *L, int *ctx);
 
 LUA_API int   (lua_pcall) (lua_State *L, int nargs, int nresults, int errfunc);
 LUA_API int   (lua_cpcall) (lua_State *L, lua_CFunction func, void *ud);
@@ -283,8 +286,6 @@ LUA_API void      (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud);
 
 #define lua_tostring(L,i)	lua_tolstring(L, (i), NULL)
 
-#define lua_call(L,n,r)		lua_callcont(L, (n), (r), NULL);
-
 
 
 /*