1 files changed, 206 insertions, 0 deletions

diff --git a/src/lua/lcorolib.c b/src/lua/lcorolib.c
new file mode 100644
index 0000000..7d6e585
--- /dev/null
+++ b/src/lua/lcorolib.c
@@ -0,0 +1,206 @@
+/*
+** $Id: lcorolib.c $
+** Coroutine Library
+** See Copyright Notice in lua.h
+*/
+
+#define lcorolib_c
+#define LUA_LIB
+
+#include "lprefix.h"
+
+
+#include <stdlib.h>
+
+#include "lua.h"
+
+#include "lauxlib.h"
+#include "lualib.h"
+
+
+static lua_State *getco (lua_State *L) {
+  lua_State *co = lua_tothread(L, 1);
+  luaL_argexpected(L, co, 1, "thread");
+  return co;
+}
+
+
+/*
+** Resumes a coroutine. Returns the number of results for non-error
+** cases or -1 for errors.
+*/
+static int auxresume (lua_State *L, lua_State *co, int narg) {
+  int status, nres;
+  if (!lua_checkstack(co, narg)) {
+    lua_pushliteral(L, "too many arguments to resume");
+    return -1;  /* error flag */
+  }
+  lua_xmove(L, co, narg);
+  status = lua_resume(co, L, narg, &nres);
+  if (status == LUA_OK || status == LUA_YIELD) {
+    if (!lua_checkstack(L, nres + 1)) {
+      lua_pop(co, nres);  /* remove results anyway */
+      lua_pushliteral(L, "too many results to resume");
+      return -1;  /* error flag */
+    }
+    lua_xmove(co, L, nres);  /* move yielded values */
+    return nres;
+  }
+  else {
+    lua_xmove(co, L, 1);  /* move error message */
+    return -1;  /* error flag */
+  }
+}
+
+
+static int luaB_coresume (lua_State *L) {
+  lua_State *co = getco(L);
+  int r;
+  r = auxresume(L, co, lua_gettop(L) - 1);
+  if (r < 0) {
+    lua_pushboolean(L, 0);
+    lua_insert(L, -2);
+    return 2;  /* return false + error message */
+  }
+  else {
+    lua_pushboolean(L, 1);
+    lua_insert(L, -(r + 1));
+    return r + 1;  /* return true + 'resume' returns */
+  }
+}
+
+
+static int luaB_auxwrap (lua_State *L) {
+  lua_State *co = lua_tothread(L, lua_upvalueindex(1));
+  int r = auxresume(L, co, lua_gettop(L));
+  if (r < 0) {
+    int stat = lua_status(co);
+    if (stat != LUA_OK && stat != LUA_YIELD)
+      lua_resetthread(co);  /* close variables in case of errors */
+    if (lua_type(L, -1) == LUA_TSTRING) {  /* error object is a string? */
+      luaL_where(L, 1);  /* add extra info, if available */
+      lua_insert(L, -2);
+      lua_concat(L, 2);
+    }
+    return lua_error(L);  /* propagate error */
+  }
+  return r;
+}
+
+
+static int luaB_cocreate (lua_State *L) {
+  lua_State *NL;
+  luaL_checktype(L, 1, LUA_TFUNCTION);
+  NL = lua_newthread(L);
+  lua_pushvalue(L, 1);  /* move function to top */
+  lua_xmove(L, NL, 1);  /* move function from L to NL */
+  return 1;
+}
+
+
+static int luaB_cowrap (lua_State *L) {
+  luaB_cocreate(L);
+  lua_pushcclosure(L, luaB_auxwrap, 1);
+  return 1;
+}
+
+
+static int luaB_yield (lua_State *L) {
+  return lua_yield(L, lua_gettop(L));
+}
+
+
+#define COS_RUN         0
+#define COS_DEAD        1
+#define COS_YIELD       2
+#define COS_NORM        3
+
+
+static const char *const statname[] =
+  {"running", "dead", "suspended", "normal"};
+
+
+static int auxstatus (lua_State *L, lua_State *co) {
+  if (L == co) return COS_RUN;
+  else {
+    switch (lua_status(co)) {
+      case LUA_YIELD:
+        return COS_YIELD;
+      case LUA_OK: {
+        lua_Debug ar;
+        if (lua_getstack(co, 0, &ar))  /* does it have frames? */
+          return COS_NORM;  /* it is running */
+        else if (lua_gettop(co) == 0)
+            return COS_DEAD;
+        else
+          return COS_YIELD;  /* initial state */
+      }
+      default:  /* some error occurred */
+        return COS_DEAD;
+    }
+  }
+}
+
+
+static int luaB_costatus (lua_State *L) {
+  lua_State *co = getco(L);
+  lua_pushstring(L, statname[auxstatus(L, co)]);
+  return 1;
+}
+
+
+static int luaB_yieldable (lua_State *L) {
+  lua_State *co = lua_isnone(L, 1) ? L : getco(L);
+  lua_pushboolean(L, lua_isyieldable(co));
+  return 1;
+}
+
+
+static int luaB_corunning (lua_State *L) {
+  int ismain = lua_pushthread(L);
+  lua_pushboolean(L, ismain);
+  return 2;
+}
+
+
+static int luaB_close (lua_State *L) {
+  lua_State *co = getco(L);
+  int status = auxstatus(L, co);
+  switch (status) {
+    case COS_DEAD: case COS_YIELD: {
+      status = lua_resetthread(co);
+      if (status == LUA_OK) {
+        lua_pushboolean(L, 1);
+        return 1;
+      }
+      else {
+        lua_pushboolean(L, 0);
+        lua_xmove(co, L, 1);  /* copy error message */
+        return 2;
+      }
+    }
+    default:  /* normal or running coroutine */
+      return luaL_error(L, "cannot close a %s coroutine", statname[status]);
+  }
+}
+
+
+static const luaL_Reg co_funcs[] = {
+  {"create", luaB_cocreate},
+  {"resume", luaB_coresume},
+  {"running", luaB_corunning},
+  {"status", luaB_costatus},
+  {"wrap", luaB_cowrap},
+  {"yield", luaB_yield},
+  {"isyieldable", luaB_yieldable},
+  {"close", luaB_close},
+  {NULL, NULL}
+};
+
+
+
+LUAMOD_API int luaopen_coroutine (lua_State *L) {
+  luaL_newlib(L, co_funcs);
+  return 1;
+}
+