AK: Allow inlining ref-count functionality

Previously we'd incur the costs for a function call via the PLT even
for the most trivial ref-count actions like increasing/decreasing the
reference count.

By moving the code to the header file we allow the compiler to inline
this code into the caller's function.

3 files changed, 33 insertions, 53 deletions

diff --git a/AK/RefCounted.cpp b/AK/RefCounted.cpp
deleted file mode 100644
index 9201c69120..0000000000
--- a/AK/RefCounted.cpp
+++ /dev/null
@@ -1,47 +0,0 @@
-/*
- * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
- *
- * SPDX-License-Identifier: BSD-2-Clause
- */
-
-#include <AK/RefCounted.h>
-
-namespace AK {
-
-RefCountedBase::~RefCountedBase()
-{
-    VERIFY(m_ref_count.load(AK::MemoryOrder::memory_order_relaxed) == 0);
-}
-
-void RefCountedBase::ref() const
-{
-    auto old_ref_count = m_ref_count.fetch_add(1, AK::MemoryOrder::memory_order_relaxed);
-    VERIFY(old_ref_count > 0);
-    VERIFY(!Checked<RefCountType>::addition_would_overflow(old_ref_count, 1));
-}
-
-[[nodiscard]] bool RefCountedBase::try_ref() const
-{
-    RefCountType expected = m_ref_count.load(AK::MemoryOrder::memory_order_relaxed);
-    for (;;) {
-        if (expected == 0)
-            return false;
-        VERIFY(!Checked<RefCountType>::addition_would_overflow(expected, 1));
-        if (m_ref_count.compare_exchange_strong(expected, expected + 1, AK::MemoryOrder::memory_order_acquire))
-            return true;
-    }
-}
-
-RefCountedBase::RefCountType RefCountedBase::ref_count() const
-{
-    return m_ref_count.load(AK::MemoryOrder::memory_order_relaxed);
-}
-
-RefCountedBase::RefCountType RefCountedBase::deref_base() const
-{
-    auto old_ref_count = m_ref_count.fetch_sub(1, AK::MemoryOrder::memory_order_acq_rel);
-    VERIFY(old_ref_count > 0);
-    return old_ref_count - 1;
-}
-
-}
diff --git a/AK/RefCounted.h b/AK/RefCounted.h
index 63ab493a8c..f99e40445e 100644
--- a/AK/RefCounted.h
+++ b/AK/RefCounted.h
@@ -47,15 +47,43 @@ public:
     using RefCountType = unsigned int;
     using AllowOwnPtr = FalseType;
 
-    void ref() const;
-    [[nodiscard]] bool try_ref() const;
-    [[nodiscard]] RefCountType ref_count() const;
+    void ref() const
+    {
+        auto old_ref_count = m_ref_count.fetch_add(1, AK::MemoryOrder::memory_order_relaxed);
+        VERIFY(old_ref_count > 0);
+        VERIFY(!Checked<RefCountType>::addition_would_overflow(old_ref_count, 1));
+    }
+
+    [[nodiscard]] bool try_ref() const
+    {
+        RefCountType expected = m_ref_count.load(AK::MemoryOrder::memory_order_relaxed);
+        for (;;) {
+            if (expected == 0)
+                return false;
+            VERIFY(!Checked<RefCountType>::addition_would_overflow(expected, 1));
+            if (m_ref_count.compare_exchange_strong(expected, expected + 1, AK::MemoryOrder::memory_order_acquire))
+                return true;
+        }
+    }
+
+    [[nodiscard]] RefCountType ref_count() const
+    {
+        return m_ref_count.load(AK::MemoryOrder::memory_order_relaxed);
+    }
 
 protected:
     RefCountedBase() = default;
-    ~RefCountedBase();
+    ~RefCountedBase()
+    {
+        VERIFY(m_ref_count.load(AK::MemoryOrder::memory_order_relaxed) == 0);
+    }
 
-    RefCountType deref_base() const;
+    RefCountType deref_base() const
+    {
+        auto old_ref_count = m_ref_count.fetch_sub(1, AK::MemoryOrder::memory_order_acq_rel);
+        VERIFY(old_ref_count > 0);
+        return old_ref_count - 1;
+    }
 
     mutable Atomic<RefCountType> m_ref_count { 1 };
 };
diff --git a/Kernel/CMakeLists.txt b/Kernel/CMakeLists.txt
index 7dd9e70424..023ab811fe 100644
--- a/Kernel/CMakeLists.txt
+++ b/Kernel/CMakeLists.txt
@@ -277,7 +277,6 @@ set(AK_SOURCES
     ../AK/JsonParser.cpp
     ../AK/JsonValue.cpp
     ../AK/LexicalPath.cpp
-    ../AK/RefCounted.cpp
     ../AK/String.cpp
     ../AK/StringBuilder.cpp
     ../AK/StringImpl.cpp