Some refactorings

Author: mjp41

CMakeLists.txt

@@ -29,6 +29,7 @@ set(CMAKE_CXX_STANDARD 20)
 add_library(
   rt OBJECT
   src/rt/rt.cc
+  src/rt/objects/region.cc
   src/rt/ui/mermaid.cc
   src/rt/core/builtin.cc
 )

src/rt/core.h

@@ -1,26 +1,11 @@
-#include "objects/dyn_object.h"
+#include "objects/prototype_object.h"
 #include "rt.h"
 
 #include <map>
 
 namespace rt::core
 {
-  class PrototypeObject : public objects::DynObject
-  {
-    std::string name;
-
-  public:
-    PrototypeObject(std::string name_, objects::DynObject* prototype = nullptr)
-    : objects::DynObject(prototype), name(name_)
-    {}
-
-    std::string get_name() override
-    {
-      std::stringstream stream;
-      stream << "[" << name << "]";
-      return stream.str();
-    }
-  };
+  using PrototypeObject = objects::PrototypeObject;
 
   inline PrototypeObject* framePrototypeObject()
   {
@@ -39,7 +24,7 @@ namespace rt::core
       if (parent_frame)
       {
         auto old_value = this->set(objects::ParentField, parent_frame);
-        add_reference(this, parent_frame);
+        objects::add_reference(this, parent_frame);
         assert(!old_value);
       }
     }

src/rt/core/builtin.cc

@@ -27,7 +27,7 @@ namespace rt::core
       {
         auto value = stack->back();
         mermaid->add_always_hide(value);
-        remove_reference(frame, value);
+        rt::remove_reference(frame, value);
         stack->pop_back();
       }
 
@@ -42,7 +42,7 @@ namespace rt::core
         auto value = stack->back();
         mermaid->remove_unreachable_hide(value);
         mermaid->remove_always_hide(value);
-        remove_reference(frame, value);
+        rt::remove_reference(frame, value);
         stack->pop_back();
       }
 
@@ -66,7 +66,7 @@ namespace rt::core
 
       auto region = pop(stack, "region for cown creation");
       auto cown = make_cown(region);
-      move_reference(frame, cown, region);
+      rt::move_reference(frame, cown, region);
 
       return cown;
     });
@@ -89,7 +89,7 @@ namespace rt::core
 
       auto value = pop(stack, "object to freeze");
       freeze(value);
-      remove_reference(frame, value);
+      rt::remove_reference(frame, value);
 
       return std::nullopt;
     });
@@ -98,8 +98,8 @@ namespace rt::core
       assert(args == 1);
 
       auto value = pop(stack, "region source");
-      create_region(value);
-      remove_reference(frame, value);
+      rt::create_region(value);
+      rt::remove_reference(frame, value);
 
       return std::nullopt;
     });

src/rt/objects/dyn_object.h

@@ -27,6 +27,11 @@ namespace rt::objects
   const std::string PrototypeField{"__proto__"};
   const std::string ParentField{"__parent__"};
 
+  Region* get_region(DynObject* obj);
+
+  Region* get_local_region();
+  void set_local_region(Region* region);
+
   // Representation of objects
   class DynObject
   {
@@ -39,8 +44,8 @@ namespace rt::objects
     friend void dealloc(DynObject* obj);
     template<typename Pre, typename Post>
     friend void visit(Edge, Pre, Post);
-
-    thread_local static RegionPointer local_region;
+    friend Region* get_region(DynObject* obj);
+    friend void add_to_region(Region* r, DynObject* target);
 
     // TODO: Not concurrency safe
     inline static size_t count{0};
@@ -53,68 +58,7 @@ namespace rt::objects
 
     std::map<std::string, DynObject*> fields{};
 
-    static Region* get_region(DynObject* obj)
-    {
-      if ((obj == nullptr) || obj->is_immutable())
-        return nullptr;
-      return obj->region.get_ptr();
-    }
-
-    bool is_local_object()
-    {
-      return region.get_ptr() == get_local_region();
-    }
-
-    static void remove_region_reference(Region* src, Region* target)
-    {
-      if (src == target)
-      {
-        std::cout << "Same region, no need to do anything" << std::endl;
-        return;
-      }
-
-      // Handle immutable case
-      if (target == nullptr)
-        return;
-
-      if (src == get_local_region())
-      {
-        Region::dec_lrc(target);
-        return;
-      }
-
-      if (src)
-      {
-        assert(target->parent == src);
-        target->parent = nullptr;
-      }
-      return;
-    }
-
-    static void add_region_reference(Region* src_region, DynObject* target)
-    {
-      if (target->is_immutable())
-        return;
-
-      auto target_region = get_region(target);
-      if (src_region == target_region)
-        return;
-
-      if (src_region == get_local_region())
-      {
-        Region::inc_lrc(target_region);
-        return;
-      }
-
-      if (target_region == get_local_region())
-      {
-        target->add_to_region(src_region);
-        return;
-      }
-
-      Region::set_parent(target_region, src_region);
-    }
-
+  public:
     size_t change_rc(signed delta)
     {
       std::cout << "Change RC: " << get_name() << " " << rc << " + " << delta
@@ -134,50 +78,6 @@ namespace rt::objects
         delta;
     }
 
-    void add_to_region(Region* r)
-    {
-      size_t internal_references{0};
-      size_t rc_of_added_objects{0};
-      visit(this, [&](Edge e) {
-        auto obj = e.target;
-        if (obj == nullptr || obj->is_immutable())
-          return false;
-
-        if (obj->is_local_object())
-        {
-          std::cout << "Adding object to region: " << obj->get_name()
-                    << " rc = " << obj->rc << std::endl;
-          rc_of_added_objects += obj->rc;
-          internal_references++;
-          obj->region = {r};
-          get_local_region()->objects.erase(obj);
-          r->objects.insert(obj);
-          return true;
-        }
-
-        auto obj_region = get_region(obj);
-        if (obj_region == r)
-        {
-          std::cout << "Adding internal reference to object: "
-                    << obj->get_name() << std::endl;
-          internal_references++;
-          return false;
-        }
-
-        Region::set_parent(obj_region, r);
-        Region::dec_lrc(obj_region);
-        return false;
-      });
-      r->local_reference_count += rc_of_added_objects - internal_references;
-
-      std::cout << "Added " << rc_of_added_objects - internal_references
-                << " to LRC of region" << std::endl;
-      std::cout << "Region LRC: " << r->local_reference_count << std::endl;
-      std::cout << "Internal references found: " << internal_references
-                << std::endl;
-    }
-
-  public:
     // prototype is borrowed, the caller does not need to provide an RC.
     DynObject(DynObject* prototype_ = nullptr, bool first_frame = false)
     : prototype(prototype_)
@@ -194,7 +94,7 @@ namespace rt::objects
       if (prototype != nullptr)
       {
         // prototype->change_rc(1);
-        add_reference(this, prototype);
+        objects::add_reference(this, prototype);
       }
       std::cout << "Allocate: " << this << std::endl;
     }
@@ -224,6 +124,11 @@ namespace rt::objects
       std::cout << "Deallocate: " << get_name() << std::endl;
     }
 
+    size_t get_rc()
+    {
+      return rc;
+    }
+
     /// @brief The string representation of this value to
     /// TODO remove virtual once we have primitive functions.
     virtual std::string get_name()
@@ -333,127 +238,17 @@ namespace rt::objects
       return prototype;
     }
 
-    static void add_reference(DynObject* src, DynObject* target)
-    {
-      if (target == nullptr)
-        return;
-
-      target->change_rc(1);
-
-      auto src_region = get_region(src);
-      add_region_reference(src_region, target);
-    }
-
-    static void
-    remove_reference(DynObject* src_initial, DynObject* old_dst_initial)
-    {
-      visit(
-        {src_initial, "", old_dst_initial},
-        [&](Edge e) {
-          if (e.target == nullptr)
-            return false;
-
-          std::cout << "Remove reference from: " << e.src->get_name() << " to "
-                    << e.target->get_name() << std::endl;
-          bool result = e.target->change_rc(-1) == 0;
-
-          remove_region_reference(get_region(e.src), get_region(e.target));
-          return result;
-        },
-        [&](DynObject* obj) { delete obj; });
-
-      Region::collect();
-    }
-
-    static void
-    move_reference(DynObject* src, DynObject* dst, DynObject* target)
-    {
-      if (target == nullptr || target->is_immutable())
-        return;
-
-      auto src_region = get_region(src);
-      auto dst_region = get_region(dst);
-
-      if (src_region == dst_region)
-        return;
-
-      auto target_region = get_region(target);
-
-      add_region_reference(dst_region, target);
-      // Note that target_region and get_region(target) are not necessarily the
-      // same.
-      remove_region_reference(src_region, target_region);
-    }
-
-    void create_region()
-    {
-      Region* r = new Region();
-      add_to_region(r);
-      // Add root reference as external.
-      r->local_reference_count++;
-    }
-
     static size_t get_count()
     {
       return count;
     }
 
-    static Region* get_local_region()
-    {
-      return local_region;
-    }
-
     static std::set<DynObject*> get_objects()
     {
       return all_objects;
     }
   };
 
-  inline void destruct(DynObject* obj)
-  {
-    // Called from the region destructor.
-    // Remove all references to other objects.
-    // If in the same region, then just remove the RC, but don't try to collect
-    // as the whole region is being torndown including any potential cycles.
-    auto same_region = [](DynObject* src, DynObject* target) {
-      return DynObject::get_region(src) == DynObject::get_region(target);
-    };
-    for (auto& [key, field] : obj->fields)
-    {
-      if (field == nullptr)
-        continue;
-      if (same_region(obj, field))
-      {
-        // Same region just remove the rc, but don't try to collect.
-        field->change_rc(-1);
-        continue;
-      }
-
-      auto old_value = obj->set(key, nullptr);
-      remove_reference(obj, old_value);
-    }
-
-    if (same_region(obj, obj->prototype))
-    {
-      obj->prototype->change_rc(-1);
-    }
-    else
-    {
-      auto old_value = obj->set_prototype(nullptr);
-      remove_reference(obj, old_value);
-    }
-  }
-
-  inline void dealloc(DynObject* obj)
-  {
-    // Called from the region destructor.
-    // So remove from region if in one.
-    // This ensures we don't try to remove it from the set that is being
-    // iterated.
-    obj->region = nullptr;
-    delete obj;
-  }
-
   template<typename Pre, typename Post>
   inline void visit(Edge e, Pre pre, Post post)
   {