More work on thread scheduling and tracebacks

luprex/core/cpp/luastack.hpp

@@ -504,7 +504,7 @@ public:
         push_any_value(value);
         lua_rawset(L_, tab);
     }
-
+    
     // template<typename VT>
     // void rawset(LuaSlot tab, const char *field, VT value) const {
     //     push_any_value(value);

luprex/core/cpp/sched.hpp

@@ -11,6 +11,7 @@ private:
     int64_t clock_;
     int64_t thread_id_;
     int64_t place_id_;
+    int func_args_;
 
 public:
     int64_t clock() const { return clock_; }

luprex/core/cpp/traceback.cpp

@@ -5,7 +5,9 @@
 
 
 // Call this with the error message on top of the stack.
-static void traceback_general(lua_State *L, lua_State *L1, int baselevel) {
+// The error message is replaced with a traceback.
+//
+int traceback_coroutine(lua_State *L) {
     int top = lua_gettop(L);
 
     // Convert message to a string
@@ -23,22 +25,24 @@ static void traceback_general(lua_State *L, lua_State *L1, int baselevel) {
 
     // Append the traceback.
     lua_Debug ar;
-    int level = baselevel;
     int firstpart = 1;
-    while (lua_getstack(L1, level++, &ar)) {
+    for (int level = 0; lua_getstack(L, level, &ar); level++) {
         if (level > TRACEBACK_LEVELS1 && firstpart) {
             /* no more than `LEVELS2' more levels? */
-            if (!lua_getstack(L1, level + TRACEBACK_LEVELS2, &ar))
+            if (!lua_getstack(L, level + TRACEBACK_LEVELS2, &ar))
                 level--; /* keep going */
             else {
                 lua_pushliteral(L, "\n\t...");                 /* too many levels */
-                while (lua_getstack(L1, level + TRACEBACK_LEVELS2, &ar)) /* find last levels */
+                while (lua_getstack(L, level + TRACEBACK_LEVELS2, &ar)) /* find last levels */
                     level++;
             }
             firstpart = 0;
             continue;
         }
-        lua_getinfo(L1, "Snl", &ar);
+        lua_getinfo(L, "Snl", &ar);
+        if ((level == 0) && (*ar.what == 'C') && (std::string(ar.name) == "__newindex")) {
+            continue;
+        }
         if ((ar.currentline > 0) || (*ar.namewhat != 0) || (*ar.what != 'C')) {
             lua_pushliteral(L, "\n\t");
             lua_pushfstring(L, "%s:", ar.short_src);
@@ -64,22 +68,14 @@ static void traceback_general(lua_State *L, lua_State *L1, int baselevel) {
     if (1 + lua_gettop(L) - top > 1) {
         lua_concat(L, 1 + lua_gettop(L) - top);
     }
-}
-
-int traceback_handler(lua_State *L) {
-    traceback_general(L, L, 1);
     return 1;
 }
 
-void traceback_coroutine(lua_State *L, lua_State *CO) {
-    lua_xmove(CO, L, 1);
-    traceback_general(L, CO, 0);
-}
 
 int traceback_pcall(lua_State *L, int narg, int nret) {
     int status;
     int base = lua_gettop(L) - narg; /* function index */
-    lua_pushcfunction(L, traceback_handler); /* push traceback function */
+    lua_pushcfunction(L, traceback_coroutine); /* push traceback function */
     lua_insert(L, base);             /* put it under chunk and args */
     status = lua_pcall(L, narg, nret, base);
     lua_remove(L, base); /* remove traceback function */

luprex/core/cpp/traceback.hpp

@@ -15,10 +15,10 @@
 
 // traceback_coroutine
 //
-// Given a coroutine which contains an error message, pop the error
+// Given a coroutine which contains an error message, replace
-// message from the coroutine, and push a traceback onto L.
+// the error message with a full traceback.  Always returns 1.
 //
-void traceback_coroutine(lua_State *L, lua_State *CO);
+int traceback_coroutine(lua_State *L);
 
 // traceback_pcall
 //

luprex/core/cpp/world.cpp

@@ -118,7 +118,6 @@ Tangible *World::tangible_make(lua_State *L, int64_t id, bool pushdb) {
 
     // Populate the database and metatable with initial stuff.
     LS.rawset(database, "inventory", LuaNewTable);
-    LS.rawset(database, "id", id);
     LS.rawset(metatab, "id", id);
     LS.rawset(metatab, "threads", LuaNewTable);
     // LS.rawset(metatab, "__metatable", LuaNil);
@@ -258,14 +257,13 @@ void World::invoke_plan(int64_t actor_id, int64_t place_id, const std::string &a
     }
     LS.rawset(threads, tid, thread);
     LS.result();
-
+    
     // Push the thread's ID into the runnable thread queue,
     // then run the thread queue.
     thread_sched_.add(0, tid, place_id);
     run_scheduled_threads(0);
 }
 
-
 void World::run_scheduled_threads(int64_t clk) {
     lua_State *L = state();
     LuaVar tangibles, place, mt, threads, thread;
@@ -293,23 +291,31 @@ void World::run_scheduled_threads(int64_t clk) {
 
         // Resume the coroutine.
         lua_State *CO = LS.ckthread(thread);
-        int status = lua_resume(CO, 3);
+        int top = lua_gettop(CO);
+        int status = lua_resume(CO, (top > 0) ? (top - 1) : 0);
 
         // Three possible outcomes: finished, yielded, or errored.
         if (status == LUA_YIELD) {
             // When the wait statement yields, it yields the desired timestamp.
-            std::cerr << "Thread yield top = " << lua_gettop(CO) << std::endl;
+            if ((lua_gettop(CO) != 1) || (!lua_isnumber(CO, 1))) {
-            // TODO: Insert the thread back into thread_sched_.
+                std::cerr << "Thread yielded incorrectly.  Killing it." << std::endl;
-            LS.rawset(threads, sched.thread_id(), LuaNil);
+                LS.rawset(threads, sched.thread_id(), LuaNil);
+            } else {
+                lua_Number delay = lua_tonumber(CO, 1);
+                lua_settop(CO, 0);
+                std::cerr << "Thread wait = " << delay << std::endl;
+                thread_sched_.add(sched.clock() + int64_t(delay), sched.thread_id(), sched.place_id());
+                std::cerr << "Added to schedule." << std::endl;
+            }
         } else if (status == 0) {
             // Successfully ran to completion.  Remove from thread table.
             std::cerr << "Thread ran to completion." << std::endl;
             LS.rawset(threads, sched.thread_id(), LuaNil);
         } else {
-            // Transfer the error message from CO to L, and add a traceback.
+            // Generated an error.  Add a traceback, print, and kill the coroutine.
+            traceback_coroutine(CO);
+            std::cerr << lua_tostring(CO, -1);
             LS.rawset(threads, sched.thread_id(), LuaNil);
-            traceback_coroutine(L, CO);
-            std::cerr << lua_tostring(L, -1);
         }
     }
     LS.result();
@@ -330,3 +336,10 @@ LuaDefine(tangible_make, "c") {
     World::fetch(L)->tangible_make(L, 0, true);
     return 1;
 }
+
+LuaDefine(world_wait, "f") {
+    if (lua_type(L, -1) != LUA_TNUMBER) {
+        luaL_error(L, "Argument to wait must be a number.");
+    }
+    return lua_yield(L, 1);
+}

luprex/core/cpp/world.hpp

@@ -61,7 +61,7 @@ public:
     PlaneMap plane_map_;
     std::unordered_map<int64_t, Tangible> tangibles_;
 
-    // Thread schedule: should include every thread, except
+    // Thread schedule: must include every thread, except
     // for the one currently-executing thread.
     //
     Schedule thread_sched_;

luprex/core/lua/player.lua

@@ -17,8 +17,12 @@ end
 
 function player.action.east(actor, place, gui)
     print("Moving east")
+    t = nil
+    t[3] = 4
 end
 
 function player.action.west(actor, place, gui)
     print("Moving west")
+    wait(0)
+    print("Moving west again")
 end