Kernel: Switch singletons to use new Singleton class

MemoryManager cannot use the Singleton class because
MemoryManager::initialize is called before the global constructors
are run. That caused the Singleton to be re-initialized, causing
it to create another MemoryManager instance.

Fixes SerenityOS#3226

AK/FlyString.cpp

@@ -27,6 +27,7 @@
 #include <AK/FlyString.h>
 #include <AK/HashTable.h>
 #include <AK/Optional.h>
+#include <AK/Singleton.h>
 #include <AK/String.h>
 #include <AK/StringUtils.h>
 #include <AK/StringView.h>
@@ -47,12 +48,11 @@ struct FlyStringImplTraits : public AK::Traits<StringImpl*> {
  }
 };
 
+static AK::Singleton<HashTable<StringImpl*, FlyStringImplTraits>> s_table;
+
 static HashTable<StringImpl*, FlyStringImplTraits>& fly_impls()
 {
- static HashTable<StringImpl*, FlyStringImplTraits>* table;
- if (!table)
- table = new HashTable<StringImpl*, FlyStringImplTraits>;
- return *table;
+ return *s_table;
 }
 
 void FlyString::did_destroy_impl(Badge<StringImpl>, StringImpl& impl)

Kernel/Singleton.h → AK/Singleton.h

@@ -26,28 +26,54 @@
 
 #pragma once
 
+#include <AK/Assertions.h>
 #include <AK/Atomic.h>
+#include <AK/kmalloc.h>
+#ifdef KERNEL
 #include <Kernel/Arch/i386/CPU.h>
+#endif
 
-namespace Kernel {
+#ifndef __serenity__
+# include <new>
+#endif
 
-template<typename T, T* (*InitFunction)()>
+namespace AK {
+
+template<typename T>
+struct SingletonInstanceCreator {
+ static T* create()
+ {
+ return new T();
+ }
+};
+
+template<typename T, T* (*InitFunction)() = SingletonInstanceCreator<T>::create>
 class Singleton {
+ AK_MAKE_NONCOPYABLE(Singleton);
+ AK_MAKE_NONMOVABLE(Singleton);
 public:
+ Singleton() = default;
+
  T* ptr() const
  {
  T* obj = AK::atomic_load(&m_obj, AK::memory_order_consume);
  if (FlatPtr(obj) <= 0x1) {
  // If this is the first time, see if we get to initialize it
- ScopedCritical critical;
+#ifdef KERNEL
+ Kernel::ScopedCritical critical;
+#endif
  if (obj == nullptr && AK::atomic_compare_exchange_strong(&m_obj, obj, (T*)0x1, AK::memory_order_acq_rel)) {
  // We're the first one
  obj = InitFunction();
  AK::atomic_store(&m_obj, obj, AK::memory_order_release);
  } else {
  // Someone else was faster, wait until they're done
  while (obj == (T*)0x1) {
- Processor::wait_check();
+#ifdef KERNEL
+ Kernel::Processor::wait_check();
+#else
+ // TODO: yield
+#endif
  obj = AK::atomic_load(&m_obj, AK::memory_order_consume);
  }
  }
@@ -93,18 +119,4 @@ class Singleton {
  mutable T* m_obj { nullptr }; // atomic
 };
 
-template<typename T>
-struct SingletonInstanceCreator {
- static T* create()
- {
- return new T();
- }
-};
-
-template<typename T>
-static Singleton<T, SingletonInstanceCreator<T>::create> make_singleton()
-{
- return Singleton<T, SingletonInstanceCreator<T>::create>();
-}
-
 }

Kernel/CommandLine.cpp

@@ -38,6 +38,7 @@ const CommandLine& kernel_command_line()
 
 void CommandLine::initialize(const String& string)
 {
+ ASSERT(!s_the);
  s_the = new CommandLine(string);
 }
 

Kernel/Console.cpp

@@ -24,6 +24,7 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <AK/Singleton.h>
 #include <Kernel/Console.h>
 #include <Kernel/IO.h>
 #include <Kernel/kstdio.h>
@@ -32,24 +33,27 @@
 // Bytes output to 0xE9 end up on the Bochs console. It's very handy.
 #define CONSOLE_OUT_TO_E9
 
-static Console* s_the;
+static AK::Singleton<Console> s_the;
 static Kernel::SpinLock g_console_lock;
 
+void Console::initialize()
+{
+ s_the.ensure_instance();
+}
+
 Console& Console::the()
 {
- ASSERT(s_the);
  return *s_the;
 }
 
 bool Console::is_initialized()
 {
- return s_the != nullptr;
+ return s_the.is_initialized();
 }
 
 Console::Console()
  : CharacterDevice(5, 1)
 {
- s_the = this;
 }
 
 Console::~Console()

Kernel/Console.h

@@ -34,6 +34,7 @@ class Console final : public Kernel::CharacterDevice {
  AK_MAKE_ETERNAL
 public:
  static Console& the();
+ static void initialize();
  static bool is_initialized();
 
  Console();

Kernel/Devices/BXVGADevice.cpp

@@ -25,6 +25,7 @@
  */
 
 #include <AK/Checked.h>
+#include <AK/Singleton.h>
 #include <Kernel/Devices/BXVGADevice.h>
 #include <Kernel/IO.h>
 #include <Kernel/PCI/Access.h>
@@ -56,7 +57,12 @@ namespace Kernel {
 #define VBE_DISPI_ENABLED 0x01
 #define VBE_DISPI_LFB_ENABLED 0x40
 
-static BXVGADevice* s_the;
+static AK::Singleton<BXVGADevice> s_the;
+
+void BXVGADevice::initialize()
+{
+ s_the.ensure_instance();
+}
 
 BXVGADevice& BXVGADevice::the()
 {
@@ -67,7 +73,6 @@ BXVGADevice::BXVGADevice()
  : BlockDevice(29, 0)
 
 {
- s_the = this;
  m_framebuffer_address = PhysicalAddress(find_framebuffer_address());
  set_safe_resolution();
 }

Kernel/Devices/BXVGADevice.h

@@ -36,6 +36,7 @@ namespace Kernel {
 class BXVGADevice final : public BlockDevice {
  AK_MAKE_ETERNAL
 public:
+ static void initialize();
  static BXVGADevice& the();
 
  BXVGADevice();

Kernel/Devices/Device.cpp

@@ -24,18 +24,17 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
+#include <AK/Singleton.h>
 #include <Kernel/Devices/Device.h>
 #include <Kernel/FileSystem/InodeMetadata.h>
 #include <LibC/errno_numbers.h>
 
 namespace Kernel {
 
-static HashMap<u32, Device*>* s_all_devices;
+static AK::Singleton<HashMap<u32, Device*>> s_all_devices;
 
 HashMap<u32, Device*>& Device::all_devices()
 {
- if (s_all_devices == nullptr)
- s_all_devices = new HashMap<u32, Device*>;
  return *s_all_devices;
 }
 

Kernel/Devices/KeyboardDevice.cpp

@@ -26,6 +26,7 @@
 
 #include <AK/Assertions.h>
 #include <AK/ByteBuffer.h>
+#include <AK/Singleton.h>
 #include <AK/StringView.h>
 #include <AK/Types.h>
 #include <Kernel/Arch/i386/CPU.h>
@@ -335,20 +336,22 @@ void KeyboardDevice::handle_irq(const RegisterState&)
  }
 }
 
-static KeyboardDevice* s_the;
+static AK::Singleton<KeyboardDevice> s_the;
+
+void KeyboardDevice::initialize()
+{
+ s_the.ensure_instance();
+}
 
 KeyboardDevice& KeyboardDevice::the()
 {
- ASSERT(s_the);
  return *s_the;
 }
 
 KeyboardDevice::KeyboardDevice()
  : IRQHandler(IRQ_KEYBOARD)
  , CharacterDevice(85, 1)
 {
- s_the = this;
-
  // Empty the buffer of any pending data.
  // I don't care what you've been pressing until now!
  while (IO::in8(I8042_STATUS) & I8042_BUFFER_FULL)

Kernel/Devices/KeyboardDevice.h

@@ -45,6 +45,7 @@ class KeyboardDevice final : public IRQHandler
 public:
  using Event = KeyEvent;
 
+ static void initialize();
  static KeyboardDevice& the();
 
  virtual ~KeyboardDevice() override;

Kernel/Devices/NullDevice.cpp

@@ -25,22 +25,26 @@
  */
 
 #include "NullDevice.h"
+#include <AK/Singleton.h>
 #include <AK/StdLibExtras.h>
 
 namespace Kernel {
 
-static NullDevice* s_the;
+static AK::Singleton<NullDevice> s_the;
+
+void NullDevice::initialize()
+{
+ s_the.ensure_instance();
+}
 
 NullDevice& NullDevice::the()
 {
- ASSERT(s_the);
  return *s_the;
 }
 
 NullDevice::NullDevice()
  : CharacterDevice(1, 3)
 {
- s_the = this;
 }
 
 NullDevice::~NullDevice()

Kernel/Devices/NullDevice.h

@@ -36,6 +36,7 @@ class NullDevice final : public CharacterDevice {
  NullDevice();
  virtual ~NullDevice() override;
 
+ static void initialize();
  static NullDevice& the();
 
 private:

Kernel/Devices/PATAChannel.cpp

@@ -25,6 +25,7 @@
  */
 
 #include <AK/ByteBuffer.h>
+#include <AK/Singleton.h>
 #include <AK/StringView.h>
 #include <Kernel/Devices/PATAChannel.h>
 #include <Kernel/Devices/PATADiskDevice.h>
@@ -106,13 +107,12 @@ namespace Kernel {
 
 #define PCI_Mass_Storage_Class 0x1
 #define PCI_IDE_Controller_Subclass 0x1
+
+static AK::Singleton<Lock> s_pata_lock;
+
 static Lock& s_lock()
 {
- static Lock* lock;
- if (!lock)
- lock = new Lock;
-
- return *lock;
+ return *s_pata_lock;
 };
 
 OwnPtr<PATAChannel> PATAChannel::create(ChannelType type, bool force_pio)

Kernel/Devices/PS2MouseDevice.cpp

@@ -25,6 +25,7 @@
  */
 
 #include <AK/Memory.h>
+#include <AK/Singleton.h>
 #include <Kernel/Devices/PS2MouseDevice.h>
 #include <Kernel/Devices/VMWareBackdoor.h>
 #include <Kernel/IO.h>
@@ -56,20 +57,24 @@ namespace Kernel {
 
 //#define PS2MOUSE_DEBUG
 
-static PS2MouseDevice* s_the;
+static AK::Singleton<PS2MouseDevice> s_the;
 
 PS2MouseDevice::PS2MouseDevice()
  : IRQHandler(IRQ_MOUSE)
  , CharacterDevice(10, 1)
 {
- s_the = this;
  initialize();
 }
 
 PS2MouseDevice::~PS2MouseDevice()
 {
 }
 
+void PS2MouseDevice::create()
+{
+ s_the.ensure_instance();
+}
+
 PS2MouseDevice& PS2MouseDevice::the()
 {
  return *s_the;

Kernel/Devices/PS2MouseDevice.h

@@ -40,6 +40,7 @@ class PS2MouseDevice final : public IRQHandler
  PS2MouseDevice();
  virtual ~PS2MouseDevice() override;
 
+ static void create();
  static PS2MouseDevice& the();
 
  // ^CharacterDevice