cleaner API for coroutines

This commit is contained in:
Roberto Ierusalimschy 2004-09-15 17:39:42 -03:00
parent 0e54d2be36
commit 2419f2bf02
7 changed files with 79 additions and 39 deletions

19
lapi.c
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@ -1,5 +1,5 @@
/* /*
** $Id: lapi.c,v 2.17 2004/08/17 17:45:45 roberto Exp roberto $ ** $Id: lapi.c,v 2.18 2004/08/30 13:44:44 roberto Exp roberto $
** Lua API ** Lua API
** See Copyright Notice in lua.h ** See Copyright Notice in lua.h
*/ */
@ -97,6 +97,7 @@ LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) {
if (from == to) return; if (from == to) return;
lua_lock(to); lua_lock(to);
api_checknelems(from, n); api_checknelems(from, n);
api_check(L, G(from) == G(to));
from->top -= n; from->top -= n;
for (i = 0; i < n; i++) { for (i = 0; i < n; i++) {
setobj2s(to, to->top, from->top + i); setobj2s(to, to->top, from->top + i);
@ -479,6 +480,15 @@ LUA_API void lua_pushlightuserdata (lua_State *L, void *p) {
} }
LUA_API int lua_pushthread (lua_State *L) {
lua_lock(L);
setthvalue(L, L->top, L);
api_incr_top(L);
lua_unlock(L);
return (G(L)->mainthread == L);
}
/* /*
** get functions (Lua -> stack) ** get functions (Lua -> stack)
@ -650,7 +660,7 @@ LUA_API int lua_setmetatable (lua_State *L, int objindex) {
case LUA_TTABLE: { case LUA_TTABLE: {
hvalue(obj)->metatable = mt; hvalue(obj)->metatable = mt;
if (mt) if (mt)
luaC_objbarrier(L, hvalue(obj), mt); luaC_objbarriert(L, hvalue(obj), mt);
break; break;
} }
case LUA_TUSERDATA: { case LUA_TUSERDATA: {
@ -816,6 +826,11 @@ LUA_API int lua_dump (lua_State *L, lua_Chunkwriter writer, void *data) {
} }
LUA_API int lua_threadstatus (lua_State *L) {
return L->status;
}
/* /*
** Garbage-collection function ** Garbage-collection function
*/ */

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@ -1,5 +1,5 @@
/* /*
** $Id: lbaselib.c,v 1.156 2004/08/30 18:35:14 roberto Exp roberto $ ** $Id: lbaselib.c,v 1.157 2004/09/03 13:16:48 roberto Exp roberto $
** Basic library ** Basic library
** See Copyright Notice in lua.h ** See Copyright Notice in lua.h
*/ */
@ -523,9 +523,13 @@ static int auxresume (lua_State *L, lua_State *co, int narg) {
int status; int status;
if (!lua_checkstack(co, narg)) if (!lua_checkstack(co, narg))
luaL_error(L, "too many arguments to resume"); luaL_error(L, "too many arguments to resume");
if (lua_threadstatus(co) == 0 && lua_gettop(co) == 0) {
lua_pushliteral(L, "cannot resume dead coroutine");
return -1; /* error flag */
}
lua_xmove(L, co, narg); lua_xmove(L, co, narg);
status = lua_resume(co, narg); status = lua_resume(co, narg);
if (status == 0) { if (status == 0 || status == LUA_YIELD) {
int nres = lua_gettop(co); int nres = lua_gettop(co);
if (!lua_checkstack(L, nres)) if (!lua_checkstack(L, nres))
luaL_error(L, "too many results to resume"); luaL_error(L, "too many results to resume");
@ -599,22 +603,44 @@ static int luaB_costatus (lua_State *L) {
luaL_argcheck(L, co, 1, "coroutine expected"); luaL_argcheck(L, co, 1, "coroutine expected");
if (L == co) lua_pushliteral(L, "running"); if (L == co) lua_pushliteral(L, "running");
else { else {
lua_Debug ar; switch (lua_threadstatus(co)) {
if (lua_getstack(co, 0, &ar) == 0 && lua_gettop(co) == 0) case LUA_YIELD:
lua_pushliteral(L, "dead"); lua_pushliteral(L, "suspended");
else break;
lua_pushliteral(L, "suspended"); case 0: {
lua_Debug ar;
if (lua_getstack(co, 0, &ar) > 0) /* does it have frames? */
lua_pushliteral(L, "normal"); /* it is running */
else if (lua_gettop(co) == 0)
lua_pushliteral(L, "dead");
else
lua_pushliteral(L, "suspended"); /* initial state */
break;
}
default: /* some error occured */
lua_pushliteral(L, "dead");
break;
}
} }
return 1; return 1;
} }
static int luaB_cocurrent (lua_State *L) {
if (lua_pushthread(L))
return 0; /* main thread is not a coroutine */
else
return 1;
}
static const luaL_reg co_funcs[] = { static const luaL_reg co_funcs[] = {
{"create", luaB_cocreate}, {"create", luaB_cocreate},
{"wrap", luaB_cowrap}, {"wrap", luaB_cowrap},
{"resume", luaB_coresume}, {"resume", luaB_coresume},
{"yield", luaB_yield}, {"yield", luaB_yield},
{"status", luaB_costatus}, {"status", luaB_costatus},
{"current", luaB_cocurrent},
{NULL, NULL} {NULL, NULL}
}; };

32
ldo.c
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@ -1,5 +1,5 @@
/* /*
** $Id: ldo.c,v 2.8 2004/09/03 15:48:56 roberto Exp roberto $ ** $Id: ldo.c,v 2.9 2004/09/08 14:23:09 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
*/ */
@ -358,7 +358,7 @@ static void resume (lua_State *L, void *ud) {
StkId firstResult; StkId firstResult;
int nargs = *cast(int *, ud); int nargs = *cast(int *, ud);
CallInfo *ci = L->ci; CallInfo *ci = L->ci;
if (!L->isSuspended) { if (L->status != LUA_YIELD) {
lua_assert(ci == L->base_ci && nargs < L->top - L->base); lua_assert(ci == L->base_ci && nargs < L->top - L->base);
luaD_precall(L, L->top - (nargs + 1), LUA_MULTRET); /* start coroutine */ luaD_precall(L, L->top - (nargs + 1), LUA_MULTRET); /* start coroutine */
} }
@ -372,10 +372,11 @@ static void resume (lua_State *L, void *ud) {
if (nresults >= 0) L->top = L->ci->top; if (nresults >= 0) L->top = L->ci->top;
} /* else yielded inside a hook: just continue its execution */ } /* else yielded inside a hook: just continue its execution */
} }
L->isSuspended = 0; L->status = 0;
firstResult = luaV_execute(L, L->ci - L->base_ci); firstResult = luaV_execute(L, L->ci - L->base_ci);
if (firstResult != NULL) /* return? */ if (firstResult != NULL) { /* return? */
luaD_poscall(L, LUA_MULTRET, firstResult); /* finalize this coroutine */ luaD_poscall(L, LUA_MULTRET, firstResult); /* finalize this coroutine */
}
} }
@ -393,25 +394,20 @@ LUA_API int lua_resume (lua_State *L, int nargs) {
lu_byte old_allowhooks; lu_byte old_allowhooks;
lua_lock(L); lua_lock(L);
lua_assert(L->errfunc == 0 && L->nCcalls == 0); lua_assert(L->errfunc == 0 && L->nCcalls == 0);
if (!L->isSuspended) { if (L->status != LUA_YIELD) {
if (L->ci == L->base_ci) { /* no activation record? */ if (L->status != 0)
if (nargs >= L->top - L->base) return resume_error(L, "cannot resume dead coroutine");
return resume_error(L, "cannot resume dead coroutine"); else if (L->ci != L->base_ci)
}
else
return resume_error(L, "cannot resume non-suspended coroutine"); return resume_error(L, "cannot resume non-suspended coroutine");
} }
old_allowhooks = L->allowhook; old_allowhooks = L->allowhook;
status = luaD_rawrunprotected(L, resume, &nargs); status = luaD_rawrunprotected(L, resume, &nargs);
if (status != 0) { /* error? */ if (status != 0) { /* error? */
L->ci = L->base_ci; /* go back to initial level */ L->status = status; /* mark thread as `dead' */
L->base = L->ci->base; seterrorobj(L, status, L->top);
L->nCcalls = 0;
luaF_close(L, L->base); /* close eventual pending closures */
seterrorobj(L, status, L->base);
L->allowhook = old_allowhooks;
restore_stack_limit(L);
} }
else
status = L->status;
lua_unlock(L); lua_unlock(L);
return status; return status;
} }
@ -431,7 +427,7 @@ LUA_API int lua_yield (lua_State *L, int nresults) {
L->top = L->base + nresults; L->top = L->base + nresults;
} }
} /* else it's an yield inside a hook: nothing to do */ } /* else it's an yield inside a hook: nothing to do */
L->isSuspended = 1; L->status = LUA_YIELD;
lua_unlock(L); lua_unlock(L);
return -1; return -1;
} }

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@ -1,5 +1,5 @@
/* /*
** $Id: lstate.c,v 2.12 2004/08/30 13:44:44 roberto Exp $ ** $Id: lstate.c,v 2.13 2004/09/08 14:23:09 roberto Exp roberto $
** Global State ** Global State
** See Copyright Notice in lua.h ** See Copyright Notice in lua.h
*/ */
@ -114,7 +114,7 @@ static void preinit_state (lua_State *L, global_State *g) {
L->openupval = NULL; L->openupval = NULL;
L->size_ci = 0; L->size_ci = 0;
L->nCcalls = 0; L->nCcalls = 0;
L->isSuspended = 0; L->status = 0;
L->base_ci = L->ci = NULL; L->base_ci = L->ci = NULL;
L->errfunc = 0; L->errfunc = 0;
setnilvalue(gt(L)); setnilvalue(gt(L));

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@ -1,5 +1,5 @@
/* /*
** $Id: lstate.h,v 2.6 2004/08/24 20:12:06 roberto Exp roberto $ ** $Id: lstate.h,v 2.7 2004/08/30 13:44:44 roberto Exp roberto $
** Global State ** Global State
** See Copyright Notice in lua.h ** See Copyright Notice in lua.h
*/ */
@ -111,7 +111,7 @@ struct lua_State {
unsigned short nCcalls; /* number of nested C calls */ unsigned short nCcalls; /* number of nested C calls */
lu_byte hookmask; lu_byte hookmask;
lu_byte allowhook; lu_byte allowhook;
lu_byte isSuspended; lu_byte status;
int basehookcount; int basehookcount;
int hookcount; int hookcount;
lua_Hook hook; lua_Hook hook;

15
lua.h
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@ -1,5 +1,5 @@
/* /*
** $Id: lua.h,v 1.191 2004/06/02 17:37:03 roberto Exp roberto $ ** $Id: lua.h,v 1.192 2004/06/04 15:30:53 roberto Exp roberto $
** Lua - An Extensible Extension Language ** Lua - An Extensible Extension Language
** Tecgraf: Computer Graphics Technology Group, PUC-Rio, Brazil ** Tecgraf: Computer Graphics Technology Group, PUC-Rio, Brazil
** http://www.lua.org mailto:info@lua.org ** http://www.lua.org mailto:info@lua.org
@ -37,11 +37,12 @@
#define lua_upvalueindex(i) (LUA_GLOBALSINDEX-(i)) #define lua_upvalueindex(i) (LUA_GLOBALSINDEX-(i))
/* error codes for `lua_pcall' */ /* return codes for `lua_pcall', `lua_resume', and `lua_threadstatus' */
#define LUA_ERRRUN 1 #define LUA_YIELD 1
#define LUA_ERRSYNTAX 2 #define LUA_ERRRUN 2
#define LUA_ERRMEM 3 #define LUA_ERRSYNTAX 3
#define LUA_ERRERR 4 #define LUA_ERRMEM 4
#define LUA_ERRERR 5
typedef struct lua_State lua_State; typedef struct lua_State lua_State;
@ -165,6 +166,7 @@ LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...);
LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n); LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n);
LUA_API void lua_pushboolean (lua_State *L, int b); LUA_API void lua_pushboolean (lua_State *L, int b);
LUA_API void lua_pushlightuserdata (lua_State *L, void *p); LUA_API void lua_pushlightuserdata (lua_State *L, void *p);
LUA_API int lua_pushthread (lua_State *L);
/* /*
@ -208,6 +210,7 @@ LUA_API int lua_dump (lua_State *L, lua_Chunkwriter writer, void *data);
*/ */
LUA_API int lua_yield (lua_State *L, int nresults); LUA_API int lua_yield (lua_State *L, int nresults);
LUA_API int lua_resume (lua_State *L, int narg); LUA_API int lua_resume (lua_State *L, int narg);
LUA_API int lua_threadstatus (lua_State *L);
/* /*
** garbage-collection function and options ** garbage-collection function and options

4
lvm.c
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@ -1,5 +1,5 @@
/* /*
** $Id: lvm.c,v 2.12 2004/08/10 19:17:23 roberto Exp roberto $ ** $Id: lvm.c,v 2.13 2004/08/12 14:19:51 roberto Exp roberto $
** Lua virtual machine ** Lua virtual machine
** See Copyright Notice in lua.h ** See Copyright Notice in lua.h
*/ */
@ -398,7 +398,7 @@ StkId luaV_execute (lua_State *L, int nexeccalls) {
if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) && if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) &&
(--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) { (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) {
traceexec(L, pc); /***/ traceexec(L, pc); /***/
if (L->isSuspended) { /* did hook yield? */ if (L->status == LUA_YIELD) { /* did hook yield? */
L->ci->savedpc = pc - 1; L->ci->savedpc = pc - 1;
return NULL; return NULL;
} }