refactor(furvm): remove executor handle

furdb/include/context.hpp

@@ -9,7 +9,7 @@
 struct context {
     furvm::context_p  context = std::make_shared<furvm::context>();
     furvm::mod_h      mod;
-    furvm::executor_h executor;
+    furvm::executor*  executor = nullptr;
     furvm::function_h mainFunction;
 
     bool running = true;

furdb/src/main.cpp

@@ -56,7 +56,7 @@ int main(int argc, char** argv) {
             std::cerr << "Failed to load module " << argv[1] << ": " << ex.what() << '\n';
             return 1;
         }
-        ctx.executor     = ctx.context->emplace_executor(ctx.context);
+        ctx.executor     = &ctx.context->allocate_executor();
         ctx.mainFunction = ctx.mod->function_at("main", furvm::function_sig{});
 
         ctx.mod->set_native_function("println", [](furvm::executor& executor) {

furvm/include/furvm/context.hpp

@@ -11,6 +11,7 @@
 
 #include <cstddef>
 #include <utility>
+#include <vector>
 
 namespace furvm {
 
@@ -39,15 +40,10 @@ public:
     context(const context&)            = delete;
     context& operator=(const context&) = delete;
 public:
-    /**
-     * @brief Emplaces an executor in the context.
-     *
-     * @param args Arguments forwarded to executor's constructor.
-     * @return A handle to the emplaced executor.
-     */
     template <typename... Args>
-    auto emplace_executor(Args&&... args) {
+    auto& allocate_executor() {
-        return m_executors.emplace_back(std::forward<Args>(args)...);
+        executor executor(this);
+        return m_executors.emplace_back(std::move(executor));
     }
 
     /**
@@ -57,7 +53,7 @@ public:
      * @return A handle to the executor.
      */
     template <typename... Args>
-    auto executor_at(Args&&... args) {
+    auto& executor_at(Args&&... args) {
         return m_executors.at(std::forward<Args>(args)...);
     }
 
@@ -68,19 +64,11 @@ public:
      * @return A handle to the executor.
      */
     template <typename... Args>
-    auto executor_at(Args&&... args) const {
+    const auto& executor_at(Args&&... args) const {
         return m_executors.at(std::forward<Args>(args)...);
     }
 
-    /**
+    const std::vector<executor>& executors() const { return m_executors; }
-     * @brief Erases an executor from the context.
-     *
-     * @param args Id of the executor.
-     */
-    template <typename... Args>
-    void erase_executor(Args&&... args) {
-        m_executors.erase(std::forward<Args>(args)...);
-    }
 public:
     template <typename... Args>
     auto emplace_thing(Args&&... args) {
@@ -128,9 +116,9 @@ public:
 
     thing_type_store& tt_store() { return m_thingTypeStore; }
 private:
-    handle_container<mod_h>      m_modules;
+    handle_container<mod_h>   m_modules;
-    handle_container<thing_h>    m_things;
+    handle_container<thing_h> m_things;
-    handle_container<executor_h> m_executors;
+    std::vector<executor>     m_executors;
 
     furlang::arena             m_thingArena;
     thing_allocator<std::byte> m_thingAllocator;

furvm/include/furvm/executor.hpp

@@ -32,6 +32,10 @@ static inline executor_flags operator~(executor_flags flags) {
 using executor_callback = std::function<void(executor&)>;
 
 class executor {
+    friend class context;
+private:
+    executor(context* context)
+      : m_context(context) {}
 public:
     /**
      * @brief Executor frame.
@@ -47,14 +51,6 @@ public:
         std::vector<thing_h> variables;  /**< Frame variables. */
     };
 public:
-    /**
-     * @brief Returns a new executor.
-     *
-     * @param context Context.
-     */
-    executor(const context_p& context)
-      : m_context(context) {}
-
     ~executor() = default;
 
     /**
@@ -181,7 +177,7 @@ private:
     thing_type* mod_to_thing_type(const mod_h& mod, const mod_type& type) const;
 private:
     executor_flags m_flags{}; // NOLINT(bugprone-invalid-enum-default-initialization)
-    context_p      m_context;
+    context*       m_context;
 
     std::stack<struct frame> m_frames;
     std::stack<thing_h>      m_stack;

furvm/include/furvm/fwd.hpp

@@ -195,21 +195,11 @@ enum class executor_flags : std::uint32_t;
  */
 class executor;
 
-/**
- * @brief An alias to a executor shared pointer.
- */
-using executor_p = std::shared_ptr<executor>;
-
 /**
  * @brief Furvm executor's index.
  */
 using executor_id = std::uint32_t;
 
-/**
- * @brief A handle to an executor.
- */
-using executor_h = handle<executor, refcount_header<executor_id>>;
-
 // context.hpp
 
 /**

furvm/src/main.cpp

@@ -80,11 +80,11 @@ int main(int argc, char** argv) {
         std::cout << '\n';
     });
 
-    furvm::executor_h executor = context->emplace_executor(context);
+    auto& executor = context->allocate_executor();
-    executor->push_frame(mod, *mainFunc);
+    executor.push_frame(mod, *mainFunc);
 
-    while ((executor->flags() & furvm::executor_flags::Done) != furvm::executor_flags::Done) {
+    while ((executor.flags() & furvm::executor_flags::Done) != furvm::executor_flags::Done) {
-        executor->step();
+        executor.step();
     }
 
     return 0;