Changeset 9fe2fd7 in mainline for uspace/lib/cpp/include/__bits/refcount_obj.hpp

Timestamp:

2019-07-24T11:44:40Z (6 years ago)

Author:

GitHub <noreply@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

a448937, f42ee6f

Parents:

9fb280c (diff), 8c0b781 (diff)
Note: this is a merge changeset, the changes displayed below correspond to the merge itself.
Use the (diff) links above to see all the changes relative to each parent.

git-author:

Jaroslav Jindrak <Dzejrou@…> (2019-07-24 11:44:40)

git-committer:

GitHub <noreply@…> (2019-07-24 11:44:40)

Message:

Merge pull request #171 from Dzejrou/hackweek

C++ stdlib: <future>

File:

• uspace/lib/cpp/include/__bits/refcount_obj.hpp (moved) (moved from uspace/lib/cpp/include/__bits/result_of.hpp ) (2 diffs)

uspace/lib/cpp/include/__bits/refcount_obj.hpp

@@ -1 +1 @@
 /*
- * Copyright (c) 2018 Jaroslav Jindrak
+ * Copyright (c) 2019 Jaroslav Jindrak
  * All rights reserved.
  *
@@ -27 +27 @@
  */
 
-#ifndef LIBCPP_BITS_RESULT_OF
-#define LIBCPP_BITS_RESULT_OF
+#ifndef LIBCPP_BITS_REFCOUNT_OBJ
+#define LIBCPP_BITS_REFCOUNT_OBJ
 
-/**
- * TODO: We have two implementations and I can't remember which
- *       one is the correnct one, investigate!
- */
-#include <__bits/invoke.hpp>
-
-namespace std
+namespace std::aux
 {
     /**
-     * Note: This doesn't work, C++14 standard allows for F
-     *       to be any complete type, our implementation
-     *       currently works like the C++11 version where
-     *       F has to be callable.
-     * TODO: Fix this.
+     * At the moment we do not have atomics, change this
+     * to std::atomic<long> once we do.
      */
+    using refcount_t = long;
 
-    template<class>
-    struct result_of;
+    class refcount_obj
+    {
+        public:
+            refcount_obj() = default;
 
-    template<class F, class... Args>
-    class result_of<F(Args...)>: aux::type_is<
-        decltype(aux::invoke(declval<F>(), declval<ArgTypes>()...))
-    >
-    { /* DUMMY BODY */ };
+            void increment() noexcept;
+            void increment_weak() noexcept;
+            bool decrement() noexcept;
+            bool decrement_weak() noexcept;
+            refcount_t refs() const noexcept;
+            refcount_t weak_refs() const noexcept;
+            bool expired() const noexcept;
 
-    template<class T>
-    using result_of_t = typename result_of<T>::type;
+            virtual ~refcount_obj() = default;
+            virtual void destroy() = 0;
+
+        protected:
+            /**
+             * We're using a trick where refcount_ > 0
+             * means weak_refcount_ has 1 added to it,
+             * this makes it easier for weak_ptrs that
+             * can't decrement the weak_refcount_ to
+             * zero with shared_ptrs using this object.
+             */
+            refcount_t refcount_{1};
+            refcount_t weak_refcount_{1};
+    };
 }