Added a thread queue

luprex/core/cpp/textgame.cpp

@@ -122,7 +122,7 @@ void TextGame::do_choose_command(const StringVec &cmd) {
     }
     std::string action = elts[index].action();
     std::cerr << "Invoking plan: " << action << std::endl;
-    world_->invoke_plan(1, gui_place_, action, &gui_);
+    world_->invoke_plan(1, gui_place_, action);
 }
 
 void TextGame::do_snapshot_command(const StringVec &cmd) {

luprex/core/cpp/world.cpp

@@ -193,7 +193,7 @@ void World::update_gui(int64_t actor_id, int64_t place_id, Gui *gui) {
     LS.result();
 }
 
-void World::invoke_plan(int64_t actor_id, int64_t place_id, const std::string &action, Gui *gui) {
+void World::invoke_plan(int64_t actor_id, int64_t place_id, const std::string &action) {
     // Validate that the action is legal.
     Gui validation_gui;
     update_gui(actor_id, place_id, &validation_gui);
@@ -201,10 +201,15 @@ void World::invoke_plan(int64_t actor_id, int64_t place_id, const std::string &a
         return;
     }
 
-    lua_State *L = state();
+    // Get an ID batch for the thread, and take one for the thread itself.
+    Tangible *tactor = tangible_get(actor_id);
+    int64_t id_batch = tactor->id_player_pool_->get_batch();
+    int64_t tid = id_batch++;
 
-    LuaVar actor, place, ugui, func, tangibles, mt, index, actions, thread, message;
-    LuaStack LS(L, actor, place, ugui, func, tangibles, mt, index, actions, thread, message);
+    // Set up for Lua manipulation.
+    lua_State *L = state();
+    LuaVar actor, place, func, tangibles, mt, index, actions, threadtab, thread, threadinfo, message;
+    LuaStack LS(L, actor, place, func, tangibles, mt, index, actions, threadtab, thread, threadinfo, message);
 
     // Get the actor and place.
     LS.rawget(tangibles, LuaRegistry, "tangibles");
@@ -237,40 +242,100 @@ void World::invoke_plan(int64_t actor_id, int64_t place_id, const std::string &a
         return;
     }
 
-    // Construct the userdata with the GUI pointer.
-    LS.newpointer<Gui>(ugui, gui, false);
-
     // Create a new thread, set up function and parameters.
     lua_State *CO = LS.newthread(thread);
     lua_pushvalue(L, func.index());
     lua_pushvalue(L, actor.index());
     lua_pushvalue(L, place.index());
-    lua_pushvalue(L, ugui.index());
+    lua_pushnil(L); // Gui state not implemented yet.
     lua_xmove(L, CO, 4);
 
-    // Resume the new coroutine.
+    // Store the thread into place's thread table.
+    LS.rawget(threadtab, mt, "threads");
+    if (!LS.istable(threadtab)) {
+        LS.result();
+        return;
+    }
+    LS.set(threadinfo, LuaNewTable);
+    LS.rawset(threadinfo, "thread", thread);
+    LS.rawset(threadtab, tid, threadinfo);
+    LS.result();
+
+    // Push the thread's ID into the runnable thread queue,
+    // then run the thread queue.
+    enqueue_thread(tid, place_id);
+    run_thread_queue();
+}
+
+void World::enqueue_thread(int64_t tid, int64_t place_id) {
+    thread_queue_.insert(std::make_pair(tid, place_id));
+}
+
+void World::run_thread(int64_t tid, int64_t place_id) {
+    lua_State *L = state();
+    LuaVar tangibles, place, mt, threads, threadtab, thread;
+    LuaStack LS(L, tangibles, place, mt, threads, threadtab, thread);
+
+    LS.rawget(tangibles, LuaRegistry, "tangibles");
+    LS.rawget(place, tangibles, place_id);
+    if (!LS.istable(place)) {
+        LS.result();
+        return;
+    }
+    LS.getmetatable(mt, place);
+    if (!LS.istable(mt)) {
+        LS.result();
+        return;
+    }
+    LS.rawget(threads, mt, "threads");
+    if (!LS.istable(threads)) {
+        LS.result();
+        return;
+    }
+    LS.rawget(threadtab, threads, tid);
+    if (!LS.istable(threadtab)) {
+        LS.result();
+        return;
+    }
+    LS.rawget(thread, threadtab, "thread");
+    if (!LS.isthread(thread)) {
+        LS.result();
+        return;
+    }
+    LS.rawset(threadtab, "wake", LuaNil);
+
+    // Resume the coroutine.
+    lua_State *CO = LS.ckthread(thread);
     int status = lua_resume(CO, 3);
 
     // Three possible outcomes: finished, yielded, or errored.
     if (status == LUA_YIELD) {
-        // Yield not implemented yet.  The coroutine is simply dropped.
-        std::cerr << "Thread yield not implemented yet." << std::endl;
+        // When the wait statement yields, it yields the desired timestamp.
+        std::cerr << "Thread yield top = " << lua_gettop(CO) << std::endl;
+        LS.rawset(threads, tid, LuaNil);
     } else if (status == 0) {
-        // Successfully ran to completion.
+        // Successfully ran to completion.  Remove from thread table.
         std::cerr << "Thread ran to completion." << std::endl;
+        LS.rawset(threads, tid, LuaNil);
     } else {
         // Transfer the error message from CO to L, and add a traceback.
+        LS.rawset(threads, tid, LuaNil);
         traceback_coroutine(L, CO);
         std::cerr << lua_tostring(L, -1);
     }
-    
-    // Nuke the userdata, in case somebody saved a pointer to it.
-    LS.clearuserdata(ugui);
-
-    // And we're done.
     LS.result();
 }
 
+void World::run_thread_queue() {
+    while (!thread_queue_.empty()) {
+        auto iter = thread_queue_.begin();
+        int64_t tid = iter->first;
+        int64_t place_id = iter->second;
+        run_thread(tid, place_id);
+        thread_queue_.erase(iter);
+    }
+}
+
 LuaDefine(tangible_get, "c") {
     LuaArg id;
     LuaRet database;

luprex/core/cpp/world.hpp

@@ -9,6 +9,8 @@
 #include "source.hpp"
 #include "gui.hpp"
 #include "luasnap.hpp"
+#include <set>
+#include <utility>
 #include <memory>
 #include <unordered_map>
 
@@ -44,6 +46,10 @@ public:
 
 class World {
 public:
+    // A thread ID appended to a place ID.
+    //
+    using ThreadPair = std::pair<int64_t, int64_t>;
+
     // A lua intepreter with snapshot function.
     //
     LuaSnap lua_snap_;
@@ -58,6 +64,14 @@ public:
     PlaneMap plane_map_;
     std::unordered_map<int64_t, Tangible> tangibles_;
 
+    // Thread queue.
+    //
+    std::set<ThreadPair> thread_queue_;
+
+    void enqueue_thread(int64_t tid, int64_t place_id);
+    void run_thread_queue();
+    void run_thread(int64_t tid, int64_t place_id);
+
 public:
     // Constructor.
     //
@@ -114,7 +128,9 @@ public:
 
     // Invoke an action plan.
     //
-    void invoke_plan(int64_t actor_id, int64_t place_id, const std::string &action, Gui *gui);
+    // Eventually we'll add another parameter for gui-state.
+    //
+    void invoke_plan(int64_t actor_id, int64_t place_id, const std::string &action);
     
     // fetch
     //

luprex/core/lua/player.lua

@@ -21,6 +21,4 @@ end
 
 function player.action.west(actor, place, gui)
     print("Moving west")
-    t = nil
-    t[3] = 5
 end