AK: Rename Retainable => RefCounted.

(And various related renames that go along with it.)

Kernel/VM/MemoryManager.cpp

@@ -324,7 +324,7 @@ bool MemoryManager::copy_on_write(Region& region, unsigned page_index_in_region)
 {
     ASSERT_INTERRUPTS_DISABLED();
     auto& vmo = region.vmo();
-    if (vmo.physical_pages()[page_index_in_region]->retain_count() == 1) {
+    if (vmo.physical_pages()[page_index_in_region]->ref_count() == 1) {
 #ifdef PAGE_FAULT_DEBUG
         dbgprintf("    >> It's a COW page but nobody is sharing it anymore. Remap r/w\n");
 #endif

Kernel/VM/PageDirectory.h

@@ -6,7 +6,7 @@
 #include <Kernel/VM/PhysicalPage.h>
 #include <Kernel/VM/RangeAllocator.h>
 
-class PageDirectory : public Retainable<PageDirectory> {
+class PageDirectory : public RefCounted<PageDirectory> {
     friend class MemoryManager;
 
 public:

Kernel/VM/PhysicalPage.h

@@ -12,13 +12,13 @@ class PhysicalPage {
 public:
     PhysicalAddress paddr() const { return m_paddr; }
 
-    void retain()
+    void ref()
     {
         ASSERT(m_retain_count);
         ++m_retain_count;
     }
 
-    void release()
+    void deref()
     {
         ASSERT(m_retain_count);
         if (!--m_retain_count) {
@@ -30,7 +30,7 @@ public:
 
     static Retained<PhysicalPage> create(PhysicalAddress, bool supervisor, bool may_return_to_freelist = true);
 
-    word retain_count() const { return m_retain_count; }
+    word ref_count() const { return m_retain_count; }
 
 private:
     PhysicalPage(PhysicalAddress paddr, bool supervisor, bool may_return_to_freelist = true);

Kernel/VM/PhysicalRegion.h

@@ -6,7 +6,7 @@
 #include <Kernel/PhysicalAddress.h>
 #include <Kernel/VM/PhysicalPage.h>
 
-class PhysicalRegion : public Retainable<PhysicalRegion> {
+class PhysicalRegion : public RefCounted<PhysicalRegion> {
     AK_MAKE_ETERNAL
 
 public:

Kernel/VM/Region.cpp

@@ -129,7 +129,7 @@ size_t Region::amount_shared() const
     size_t bytes = 0;
     for (size_t i = 0; i < page_count(); ++i) {
         auto& physical_page = m_vmo->physical_pages()[first_page_index() + i];
-        if (physical_page && physical_page->retain_count() > 1)
+        if (physical_page && physical_page->ref_count() > 1)
             bytes += PAGE_SIZE;
     }
     return bytes;

Kernel/VM/Region.h

@@ -8,7 +8,7 @@
 class Inode;
 class VMObject;
 
-class Region : public Retainable<Region> {
+class Region : public RefCounted<Region> {
     friend class MemoryManager;
 
 public:

Kernel/VM/VMObject.h

@@ -13,7 +13,7 @@
 class Inode;
 class PhysicalPage;
 
-class VMObject : public Retainable<VMObject>
+class VMObject : public RefCounted<VMObject>
     , public Weakable<VMObject> {
     friend class MemoryManager;