From 8925ad3fa08102c4c4ff2ef36cf5570ddf27c8cd Mon Sep 17 00:00:00 2001
From: Andreas Kling <kling@serenityos.org>
Date: Sat, 22 Aug 2020 16:34:49 +0200
Subject: [PATCH] Revert "Kernel: Move Singleton class to AK"

This reverts commit f0906250a181c831508a45434b9f645ff98f33e4.
---
 AK/FlyString.cpp                        |  8 ++++----
 Kernel/Console.cpp                      |  4 ++--
 Kernel/Devices/BXVGADevice.cpp          |  4 ++--
 Kernel/Devices/Device.cpp               |  4 ++--
 Kernel/Devices/KeyboardDevice.cpp       |  4 ++--
 Kernel/Devices/NullDevice.cpp           |  4 ++--
 Kernel/Devices/PATAChannel.cpp          |  4 ++--
 Kernel/Devices/PS2MouseDevice.cpp       |  4 ++--
 Kernel/Devices/SB16.cpp                 |  4 ++--
 Kernel/Devices/VMWareBackdoor.cpp       |  4 ++--
 Kernel/FileSystem/DevPtsFS.cpp          |  4 ++--
 Kernel/FileSystem/FIFO.cpp              |  4 ++--
 Kernel/FileSystem/FileSystem.cpp        |  4 ++--
 Kernel/FileSystem/Inode.cpp             |  4 ++--
 Kernel/FileSystem/VirtualFileSystem.cpp |  4 ++--
 Kernel/Interrupts/APIC.cpp              |  4 ++--
 Kernel/Net/IPv4Socket.cpp               |  4 ++--
 Kernel/Net/LocalSocket.cpp              |  4 ++--
 Kernel/Net/LoopbackAdapter.cpp          |  4 ++--
 Kernel/Net/NetworkAdapter.cpp           |  4 ++--
 Kernel/Net/Routing.cpp                  |  4 ++--
 Kernel/Net/TCPSocket.cpp                | 13 +++++++------
 Kernel/Net/UDPSocket.cpp                |  4 ++--
 Kernel/Random.cpp                       |  4 ++--
 Kernel/SharedBuffer.cpp                 |  4 ++--
 {AK => Kernel}/Singleton.h              | 25 ++++---------------------
 Kernel/TTY/PTYMultiplexer.cpp           |  4 ++--
 Kernel/Time/TimeManagement.cpp          |  4 ++--
 Kernel/TimerQueue.cpp                   |  4 ++--
 Kernel/VM/MemoryManager.cpp             |  4 ++--
 Kernel/VM/PageDirectory.cpp             |  4 ++--
 31 files changed, 71 insertions(+), 87 deletions(-)
 rename {AK => Kernel}/Singleton.h (87%)

diff --git a/AK/FlyString.cpp b/AK/FlyString.cpp
index e6e369c3f620f3..fdf2eed56afd4a 100644
--- a/AK/FlyString.cpp
+++ b/AK/FlyString.cpp
@@ -27,7 +27,6 @@
 #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>
@@ -48,11 +47,12 @@ struct FlyStringImplTraits : public AK::Traits<StringImpl*> {
     }
 };
 
-static auto s_table = make_singleton<HashTable<StringImpl*, FlyStringImplTraits>>();
-
 static HashTable<StringImpl*, FlyStringImplTraits>& fly_impls()
 {
-    return *s_table;
+    static HashTable<StringImpl*, FlyStringImplTraits>* table;
+    if (!table)
+        table = new HashTable<StringImpl*, FlyStringImplTraits>;
+    return *table;
 }
 
 void FlyString::did_destroy_impl(Badge<StringImpl>, StringImpl& impl)
diff --git a/Kernel/Console.cpp b/Kernel/Console.cpp
index c3fa023521768e..f1416cb535067b 100644
--- a/Kernel/Console.cpp
+++ b/Kernel/Console.cpp
@@ -24,16 +24,16 @@
  * 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>
+#include <Kernel/Singleton.h>
 #include <Kernel/SpinLock.h>
 
 // Bytes output to 0xE9 end up on the Bochs console. It's very handy.
 #define CONSOLE_OUT_TO_E9
 
-static auto s_the = AK::make_singleton<Console>();
+static auto s_the = Kernel::make_singleton<Console>();
 static Kernel::SpinLock g_console_lock;
 
 void Console::initialize()
diff --git a/Kernel/Devices/BXVGADevice.cpp b/Kernel/Devices/BXVGADevice.cpp
index ee822dac29b3f1..c31e6ec1f1c81f 100644
--- a/Kernel/Devices/BXVGADevice.cpp
+++ b/Kernel/Devices/BXVGADevice.cpp
@@ -25,11 +25,11 @@
  */
 
 #include <AK/Checked.h>
-#include <AK/Singleton.h>
 #include <Kernel/Devices/BXVGADevice.h>
 #include <Kernel/IO.h>
 #include <Kernel/PCI/Access.h>
 #include <Kernel/Process.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/VM/AnonymousVMObject.h>
 #include <Kernel/VM/MemoryManager.h>
 #include <LibC/errno_numbers.h>
@@ -57,7 +57,7 @@ namespace Kernel {
 #define VBE_DISPI_ENABLED 0x01
 #define VBE_DISPI_LFB_ENABLED 0x40
 
-static auto s_the = AK::make_singleton<BXVGADevice>();
+static auto s_the = make_singleton<BXVGADevice>();
 
 void BXVGADevice::initialize()
 {
diff --git a/Kernel/Devices/Device.cpp b/Kernel/Devices/Device.cpp
index e08a0ac6f510a7..d89a57506c31b1 100644
--- a/Kernel/Devices/Device.cpp
+++ b/Kernel/Devices/Device.cpp
@@ -24,14 +24,14 @@
  * 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 <Kernel/Singleton.h>
 #include <LibC/errno_numbers.h>
 
 namespace Kernel {
 
-static auto s_all_devices = AK::make_singleton<HashMap<u32, Device*>>();
+static auto s_all_devices = make_singleton<HashMap<u32, Device*>>();
 
 HashMap<u32, Device*>& Device::all_devices()
 {
diff --git a/Kernel/Devices/KeyboardDevice.cpp b/Kernel/Devices/KeyboardDevice.cpp
index 192b54c721b4a0..2fd53797e6bdf4 100644
--- a/Kernel/Devices/KeyboardDevice.cpp
+++ b/Kernel/Devices/KeyboardDevice.cpp
@@ -26,12 +26,12 @@
 
 #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>
 #include <Kernel/Devices/KeyboardDevice.h>
 #include <Kernel/IO.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/TTY/VirtualConsole.h>
 
 //#define KEYBOARD_DEBUG
@@ -336,7 +336,7 @@ void KeyboardDevice::handle_irq(const RegisterState&)
     }
 }
 
-static auto s_the = AK::make_singleton<KeyboardDevice>();
+static auto s_the = make_singleton<KeyboardDevice>();
 
 void KeyboardDevice::initialize()
 {
diff --git a/Kernel/Devices/NullDevice.cpp b/Kernel/Devices/NullDevice.cpp
index e879759d1de5bf..5e64920accc990 100644
--- a/Kernel/Devices/NullDevice.cpp
+++ b/Kernel/Devices/NullDevice.cpp
@@ -25,12 +25,12 @@
  */
 
 #include "NullDevice.h"
-#include <AK/Singleton.h>
 #include <AK/StdLibExtras.h>
+#include <Kernel/Singleton.h>
 
 namespace Kernel {
 
-static auto s_the = AK::make_singleton<NullDevice>();
+static auto s_the = make_singleton<NullDevice>();
 
 void NullDevice::initialize()
 {
diff --git a/Kernel/Devices/PATAChannel.cpp b/Kernel/Devices/PATAChannel.cpp
index 553acd412b819c..59295e5373fd4d 100644
--- a/Kernel/Devices/PATAChannel.cpp
+++ b/Kernel/Devices/PATAChannel.cpp
@@ -25,13 +25,13 @@
  */
 
 #include <AK/ByteBuffer.h>
-#include <AK/Singleton.h>
 #include <AK/StringView.h>
 #include <Kernel/Devices/PATAChannel.h>
 #include <Kernel/Devices/PATADiskDevice.h>
 #include <Kernel/FileSystem/ProcFS.h>
 #include <Kernel/IO.h>
 #include <Kernel/Process.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/VM/MemoryManager.h>
 
 namespace Kernel {
@@ -108,7 +108,7 @@ namespace Kernel {
 #define PCI_Mass_Storage_Class 0x1
 #define PCI_IDE_Controller_Subclass 0x1
 
-static auto s_pata_lock = AK::make_singleton<Lock>();
+static auto s_pata_lock = make_singleton<Lock>();
 
 static Lock& s_lock()
 {
diff --git a/Kernel/Devices/PS2MouseDevice.cpp b/Kernel/Devices/PS2MouseDevice.cpp
index 913b6d5c73e9a2..dfb5f01bec396b 100644
--- a/Kernel/Devices/PS2MouseDevice.cpp
+++ b/Kernel/Devices/PS2MouseDevice.cpp
@@ -25,10 +25,10 @@
  */
 
 #include <AK/Memory.h>
-#include <AK/Singleton.h>
 #include <Kernel/Devices/PS2MouseDevice.h>
 #include <Kernel/Devices/VMWareBackdoor.h>
 #include <Kernel/IO.h>
+#include <Kernel/Singleton.h>
 
 namespace Kernel {
 
@@ -57,7 +57,7 @@ namespace Kernel {
 
 //#define PS2MOUSE_DEBUG
 
-static auto s_the = AK::make_singleton<PS2MouseDevice>();
+static auto s_the = make_singleton<PS2MouseDevice>();
 
 PS2MouseDevice::PS2MouseDevice()
     : IRQHandler(IRQ_MOUSE)
diff --git a/Kernel/Devices/SB16.cpp b/Kernel/Devices/SB16.cpp
index 8e5611a8369852..38f81f26805371 100644
--- a/Kernel/Devices/SB16.cpp
+++ b/Kernel/Devices/SB16.cpp
@@ -25,13 +25,13 @@
  */
 
 #include <AK/Memory.h>
-#include <AK/Singleton.h>
 #include <AK/StringView.h>
 #include <Kernel/Devices/SB16.h>
 #include <Kernel/Thread.h>
 #include <Kernel/VM/AnonymousVMObject.h>
 #include <Kernel/VM/MemoryManager.h>
 #include <Kernel/IO.h>
+#include <Kernel/Singleton.h>
 
 //#define SB16_DEBUG
 
@@ -77,7 +77,7 @@ void SB16::set_sample_rate(uint16_t hz)
     dsp_write((u8)hz);
 }
 
-static auto s_the = AK::make_singleton<SB16>();
+static auto s_the = make_singleton<SB16>();
 
 SB16::SB16()
     : IRQHandler(SB16_DEFAULT_IRQ)
diff --git a/Kernel/Devices/VMWareBackdoor.cpp b/Kernel/Devices/VMWareBackdoor.cpp
index 04499e522a7c4b..8ba15600daf691 100644
--- a/Kernel/Devices/VMWareBackdoor.cpp
+++ b/Kernel/Devices/VMWareBackdoor.cpp
@@ -26,13 +26,13 @@
 
 #include <AK/Assertions.h>
 #include <AK/OwnPtr.h>
-#include <AK/Singleton.h>
 #include <AK/String.h>
 #include <Kernel/Arch/i386/CPU.h>
 #include <Kernel/CommandLine.h>
 #include <Kernel/Devices/VMWareBackdoor.h>
 #include <Kernel/API/MousePacket.h>
 #include <Kernel/IO.h>
+#include <Kernel/Singleton.h>
 
 namespace Kernel {
 
@@ -111,7 +111,7 @@ class VMWareBackdoorDetector
     OwnPtr<VMWareBackdoor> m_backdoor;
 };
 
-static auto s_vmware_backdoor = AK::make_singleton<VMWareBackdoorDetector>();
+static auto s_vmware_backdoor = make_singleton<VMWareBackdoorDetector>();
 
 VMWareBackdoor* VMWareBackdoor::the()
 {
diff --git a/Kernel/FileSystem/DevPtsFS.cpp b/Kernel/FileSystem/DevPtsFS.cpp
index 2849b8f58b21f3..b3db215c5dcab4 100644
--- a/Kernel/FileSystem/DevPtsFS.cpp
+++ b/Kernel/FileSystem/DevPtsFS.cpp
@@ -24,11 +24,11 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <AK/Singleton.h>
 #include <AK/StringBuilder.h>
 #include <AK/StringView.h>
 #include <Kernel/FileSystem/DevPtsFS.h>
 #include <Kernel/FileSystem/VirtualFileSystem.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/TTY/SlavePTY.h>
 
 namespace Kernel {
@@ -46,7 +46,7 @@ DevPtsFS::~DevPtsFS()
 {
 }
 
-static auto s_ptys = AK::make_singleton<HashTable<unsigned>>();
+static auto s_ptys = make_singleton<HashTable<unsigned>>();
 
 bool DevPtsFS::initialize()
 {
diff --git a/Kernel/FileSystem/FIFO.cpp b/Kernel/FileSystem/FIFO.cpp
index 52daa26f50d06c..670266cbcebfff 100644
--- a/Kernel/FileSystem/FIFO.cpp
+++ b/Kernel/FileSystem/FIFO.cpp
@@ -25,20 +25,20 @@
  */
 
 #include <AK/HashTable.h>
-#include <AK/Singleton.h>
 #include <AK/StdLibExtras.h>
 #include <AK/StringView.h>
 #include <Kernel/FileSystem/FIFO.h>
 #include <Kernel/FileSystem/FileDescription.h>
 #include <Kernel/Lock.h>
 #include <Kernel/Process.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/Thread.h>
 
 //#define FIFO_DEBUG
 
 namespace Kernel {
 
-static auto s_table = AK::make_singleton<Lockable<HashTable<FIFO*>>>();
+static auto s_table = make_singleton<Lockable<HashTable<FIFO*>>>();
 
 static Lockable<HashTable<FIFO*>>& all_fifos()
 {
diff --git a/Kernel/FileSystem/FileSystem.cpp b/Kernel/FileSystem/FileSystem.cpp
index 2a96fb6e6c41e5..450f401253b8de 100644
--- a/Kernel/FileSystem/FileSystem.cpp
+++ b/Kernel/FileSystem/FileSystem.cpp
@@ -26,19 +26,19 @@
 
 #include <AK/Assertions.h>
 #include <AK/HashMap.h>
-#include <AK/Singleton.h>
 #include <AK/StringBuilder.h>
 #include <AK/StringView.h>
 #include <Kernel/FileSystem/FileSystem.h>
 #include <Kernel/FileSystem/Inode.h>
 #include <Kernel/Net/LocalSocket.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/VM/MemoryManager.h>
 #include <LibC/errno_numbers.h>
 
 namespace Kernel {
 
 static u32 s_lastFileSystemID;
-static auto s_fs_map = AK::make_singleton<HashMap<u32, FS*>>();
+static auto s_fs_map = make_singleton<HashMap<u32, FS*>>();
 
 static HashMap<u32, FS*>& all_fses()
 {
diff --git a/Kernel/FileSystem/Inode.cpp b/Kernel/FileSystem/Inode.cpp
index edfba2eac98918..c136ffc2a0b846 100644
--- a/Kernel/FileSystem/Inode.cpp
+++ b/Kernel/FileSystem/Inode.cpp
@@ -25,7 +25,6 @@
  */
 
 #include <AK/NonnullRefPtrVector.h>
-#include <AK/Singleton.h>
 #include <AK/StringBuilder.h>
 #include <AK/StringView.h>
 #include <Kernel/FileSystem/Custody.h>
@@ -34,12 +33,13 @@
 #include <Kernel/FileSystem/VirtualFileSystem.h>
 #include <Kernel/KBufferBuilder.h>
 #include <Kernel/Net/LocalSocket.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/VM/SharedInodeVMObject.h>
 
 namespace Kernel {
 
 static SpinLock s_all_inodes_lock;
-static auto s_list = AK::make_singleton<InlineLinkedList<Inode>>();
+static auto s_list = make_singleton<InlineLinkedList<Inode>>();
 
 InlineLinkedList<Inode>& Inode::all_with_lock()
 {
diff --git a/Kernel/FileSystem/VirtualFileSystem.cpp b/Kernel/FileSystem/VirtualFileSystem.cpp
index 9ea1a2d5c73516..cc0510a57021cb 100644
--- a/Kernel/FileSystem/VirtualFileSystem.cpp
+++ b/Kernel/FileSystem/VirtualFileSystem.cpp
@@ -25,7 +25,6 @@
  */
 
 #include <AK/LexicalPath.h>
-#include <AK/Singleton.h>
 #include <AK/StringBuilder.h>
 #include <Kernel/Devices/BlockDevice.h>
 #include <Kernel/FileSystem/Custody.h>
@@ -35,13 +34,14 @@
 #include <Kernel/FileSystem/VirtualFileSystem.h>
 #include <Kernel/KSyms.h>
 #include <Kernel/Process.h>
+#include <Kernel/Singleton.h>
 #include <LibC/errno_numbers.h>
 
 //#define VFS_DEBUG
 
 namespace Kernel {
 
-static auto s_the = AK::make_singleton<VFS>();
+static auto s_the = make_singleton<VFS>();
 static constexpr int symlink_recursion_limit { 5 }; // FIXME: increase?
 static constexpr int root_mount_flags = MS_NODEV | MS_NOSUID | MS_RDONLY;
 
diff --git a/Kernel/Interrupts/APIC.cpp b/Kernel/Interrupts/APIC.cpp
index d92416ab9cf28a..d3e86af19de945 100644
--- a/Kernel/Interrupts/APIC.cpp
+++ b/Kernel/Interrupts/APIC.cpp
@@ -26,7 +26,6 @@
 
 #include <AK/Assertions.h>
 #include <AK/Memory.h>
-#include <AK/Singleton.h>
 #include <AK/StringView.h>
 #include <AK/Types.h>
 #include <Kernel/ACPI/Parser.h>
@@ -35,6 +34,7 @@
 #include <Kernel/IO.h>
 #include <Kernel/Interrupts/APIC.h>
 #include <Kernel/Interrupts/SpuriousInterruptHandler.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/Thread.h>
 #include <Kernel/VM/MemoryManager.h>
 #include <Kernel/VM/PageDirectory.h>
@@ -69,7 +69,7 @@
 
 namespace Kernel {
 
-static auto s_apic = AK::make_singleton<APIC>();
+static auto s_apic = make_singleton<APIC>();
 
 class APICIPIInterruptHandler final : public GenericInterruptHandler {
 public:
diff --git a/Kernel/Net/IPv4Socket.cpp b/Kernel/Net/IPv4Socket.cpp
index 2861f1a90e3c25..8286e5a2e8d4ce 100644
--- a/Kernel/Net/IPv4Socket.cpp
+++ b/Kernel/Net/IPv4Socket.cpp
@@ -24,8 +24,8 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <AK/Singleton.h>
 #include <AK/StringBuilder.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/FileSystem/FileDescription.h>
 #include <Kernel/Net/ARP.h>
 #include <Kernel/Net/ICMP.h>
@@ -46,7 +46,7 @@
 
 namespace Kernel {
 
-static auto s_table = AK::make_singleton<Lockable<HashTable<IPv4Socket*>>>();
+static auto s_table = make_singleton<Lockable<HashTable<IPv4Socket*>>>();
 
 Lockable<HashTable<IPv4Socket*>>& IPv4Socket::all_sockets()
 {
diff --git a/Kernel/Net/LocalSocket.cpp b/Kernel/Net/LocalSocket.cpp
index 6750f934038640..c703cc8ac6447e 100644
--- a/Kernel/Net/LocalSocket.cpp
+++ b/Kernel/Net/LocalSocket.cpp
@@ -24,12 +24,12 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <AK/Singleton.h>
 #include <AK/StringBuilder.h>
 #include <Kernel/FileSystem/FileDescription.h>
 #include <Kernel/FileSystem/VirtualFileSystem.h>
 #include <Kernel/Net/LocalSocket.h>
 #include <Kernel/Process.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/StdLib.h>
 #include <Kernel/UnixTypes.h>
 #include <LibC/errno_numbers.h>
@@ -38,7 +38,7 @@
 
 namespace Kernel {
 
-static auto s_list = AK::make_singleton<Lockable<InlineLinkedList<LocalSocket>>>();
+static auto s_list = make_singleton<Lockable<InlineLinkedList<LocalSocket>>>();
 
 Lockable<InlineLinkedList<LocalSocket>>& LocalSocket::all_sockets()
 {
diff --git a/Kernel/Net/LoopbackAdapter.cpp b/Kernel/Net/LoopbackAdapter.cpp
index 6b858c9549f06e..27faa8bfadbef6 100644
--- a/Kernel/Net/LoopbackAdapter.cpp
+++ b/Kernel/Net/LoopbackAdapter.cpp
@@ -24,12 +24,12 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <AK/Singleton.h>
 #include <Kernel/Net/LoopbackAdapter.h>
+#include <Kernel/Singleton.h>
 
 namespace Kernel {
 
-static auto s_loopback = AK::make_singleton<LoopbackAdapter>();
+static auto s_loopback = make_singleton<LoopbackAdapter>();
 
 LoopbackAdapter& LoopbackAdapter::the()
 {
diff --git a/Kernel/Net/NetworkAdapter.cpp b/Kernel/Net/NetworkAdapter.cpp
index 898c95d7102840..936bf9a2e7f281 100644
--- a/Kernel/Net/NetworkAdapter.cpp
+++ b/Kernel/Net/NetworkAdapter.cpp
@@ -25,7 +25,6 @@
  */
 
 #include <AK/HashTable.h>
-#include <AK/Singleton.h>
 #include <AK/StringBuilder.h>
 #include <Kernel/Heap/kmalloc.h>
 #include <Kernel/Lock.h>
@@ -34,11 +33,12 @@
 #include <Kernel/Net/LoopbackAdapter.h>
 #include <Kernel/Net/NetworkAdapter.h>
 #include <Kernel/Random.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/StdLib.h>
 
 namespace Kernel {
 
-static auto s_table = AK::make_singleton<Lockable<HashTable<NetworkAdapter*>>>();
+static auto s_table = make_singleton<Lockable<HashTable<NetworkAdapter*>>>();
 
 static Lockable<HashTable<NetworkAdapter*>>& all_adapters()
 {
diff --git a/Kernel/Net/Routing.cpp b/Kernel/Net/Routing.cpp
index d73704cccfbad6..5f72ab1166248f 100644
--- a/Kernel/Net/Routing.cpp
+++ b/Kernel/Net/Routing.cpp
@@ -25,16 +25,16 @@
  */
 
 #include <AK/HashMap.h>
-#include <AK/Singleton.h>
 #include <Kernel/Net/LoopbackAdapter.h>
 #include <Kernel/Net/Routing.h>
 #include <Kernel/Thread.h>
+#include <Kernel/Singleton.h>
 
 //#define ROUTING_DEBUG
 
 namespace Kernel {
 
-static auto s_arp_table = AK::make_singleton<Lockable<HashMap<IPv4Address, MACAddress>>>();
+static auto s_arp_table = make_singleton<Lockable<HashMap<IPv4Address, MACAddress>>>();
 
 Lockable<HashMap<IPv4Address, MACAddress>>& arp_table()
 {
diff --git a/Kernel/Net/TCPSocket.cpp b/Kernel/Net/TCPSocket.cpp
index af7f5bb9f46a43..7b8c12a49cdb27 100644
--- a/Kernel/Net/TCPSocket.cpp
+++ b/Kernel/Net/TCPSocket.cpp
@@ -24,7 +24,6 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <AK/Singleton.h>
 #include <AK/Time.h>
 #include <Kernel/Devices/RandomDevice.h>
 #include <Kernel/FileSystem/FileDescription.h>
@@ -34,6 +33,7 @@
 #include <Kernel/Net/TCPSocket.h>
 #include <Kernel/Process.h>
 #include <Kernel/Random.h>
+#include <Kernel/Singleton.h>
 
 //#define TCP_SOCKET_DEBUG
 
@@ -63,18 +63,19 @@ void TCPSocket::set_state(State new_state)
     }
 }
 
-static auto s_socket_closing = AK::make_singleton<Lockable<HashMap<IPv4SocketTuple, RefPtr<TCPSocket>>>>();
-
 Lockable<HashMap<IPv4SocketTuple, RefPtr<TCPSocket>>>& TCPSocket::closing_sockets()
 {
-    return *s_socket_closing;
+    static Lockable<HashMap<IPv4SocketTuple, RefPtr<TCPSocket>>>* s_map;
+    if (!s_map)
+        s_map = new Lockable<HashMap<IPv4SocketTuple, RefPtr<TCPSocket>>>;
+    return *s_map;
 }
 
-static auto s_socket_tuples = AK::make_singleton<Lockable<HashMap<IPv4SocketTuple, TCPSocket*>>>();
+static auto s_map = make_singleton<Lockable<HashMap<IPv4SocketTuple, TCPSocket*>>>();
 
 Lockable<HashMap<IPv4SocketTuple, TCPSocket*>>& TCPSocket::sockets_by_tuple()
 {
-    return *s_socket_tuples;
+    return *s_map;
 }
 
 RefPtr<TCPSocket> TCPSocket::from_tuple(const IPv4SocketTuple& tuple)
diff --git a/Kernel/Net/UDPSocket.cpp b/Kernel/Net/UDPSocket.cpp
index 27901a2e822bd4..ad5769667597a8 100644
--- a/Kernel/Net/UDPSocket.cpp
+++ b/Kernel/Net/UDPSocket.cpp
@@ -24,7 +24,6 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <AK/Singleton.h>
 #include <Kernel/Devices/RandomDevice.h>
 #include <Kernel/Net/NetworkAdapter.h>
 #include <Kernel/Net/Routing.h>
@@ -32,6 +31,7 @@
 #include <Kernel/Net/UDPSocket.h>
 #include <Kernel/Process.h>
 #include <Kernel/Random.h>
+#include <Kernel/Singleton.h>
 
 namespace Kernel {
 
@@ -42,7 +42,7 @@ void UDPSocket::for_each(Function<void(const UDPSocket&)> callback)
         callback(*it.value);
 }
 
-static auto s_map = AK::make_singleton<Lockable<HashMap<u16, UDPSocket*>>>();
+static auto s_map = make_singleton<Lockable<HashMap<u16, UDPSocket*>>>();
 
 Lockable<HashMap<u16, UDPSocket*>>& UDPSocket::sockets_by_port()
 {
diff --git a/Kernel/Random.cpp b/Kernel/Random.cpp
index 472f4519c572c8..b01b4aa5da6cee 100644
--- a/Kernel/Random.cpp
+++ b/Kernel/Random.cpp
@@ -25,15 +25,15 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <AK/Singleton.h>
 #include <Kernel/Arch/i386/CPU.h>
 #include <Kernel/Devices/RandomDevice.h>
 #include <Kernel/Random.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/Time/TimeManagement.h>
 
 namespace Kernel {
 
-static auto s_the = AK::make_singleton<KernelRng>();
+static auto s_the = make_singleton<KernelRng>();
 
 KernelRng& KernelRng::the()
 {
diff --git a/Kernel/SharedBuffer.cpp b/Kernel/SharedBuffer.cpp
index a5186773a4f230..49401e15e01381 100644
--- a/Kernel/SharedBuffer.cpp
+++ b/Kernel/SharedBuffer.cpp
@@ -24,13 +24,13 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <AK/Singleton.h>
 #include <Kernel/Process.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/SharedBuffer.h>
 
 namespace Kernel {
 
-static auto s_map = AK::make_singleton<Lockable<HashMap<int, NonnullOwnPtr<SharedBuffer>>>>();
+static auto s_map = make_singleton<Lockable<HashMap<int, NonnullOwnPtr<SharedBuffer>>>>();
 
 Lockable<HashMap<int, NonnullOwnPtr<SharedBuffer>>>& shared_buffers()
 {
diff --git a/AK/Singleton.h b/Kernel/Singleton.h
similarity index 87%
rename from AK/Singleton.h
rename to Kernel/Singleton.h
index 57962e3176869a..5271aa08eeeacc 100644
--- a/AK/Singleton.h
+++ b/Kernel/Singleton.h
@@ -26,33 +26,20 @@
 
 #pragma once
 
-#include <AK/Assertions.h>
 #include <AK/Atomic.h>
-#include <AK/kmalloc.h>
-#ifdef KERNEL
 #include <Kernel/Arch/i386/CPU.h>
-#endif
 
-#ifndef __serenity__
-#    include <new>
-#endif
-
-namespace AK {
+namespace Kernel {
 
 template<typename T, T* (*InitFunction)()>
 class Singleton {
-    AK_MAKE_NONCOPYABLE(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
-#ifdef KERNEL
-            Kernel::ScopedCritical critical;
-#endif
+            ScopedCritical critical;
             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();
@@ -60,11 +47,7 @@ class Singleton {
             } else {
                 // Someone else was faster, wait until they're done
                 while (obj == (T*)0x1) {
-#ifdef KERNEL
-                    Kernel::Processor::wait_check();
-#else
-                    // TODO: yield
-#endif
+                    Processor::wait_check();
                     obj = AK::atomic_load(&m_obj, AK::memory_order_consume);
                 }
             }
@@ -119,7 +102,7 @@ struct SingletonInstanceCreator {
 };
 
 template<typename T>
-inline Singleton<T, SingletonInstanceCreator<T>::create> make_singleton()
+static Singleton<T, SingletonInstanceCreator<T>::create> make_singleton()
 {
     return Singleton<T, SingletonInstanceCreator<T>::create>();
 }
diff --git a/Kernel/TTY/PTYMultiplexer.cpp b/Kernel/TTY/PTYMultiplexer.cpp
index c44a565ae9ba5b..4f8d48806e7ad4 100644
--- a/Kernel/TTY/PTYMultiplexer.cpp
+++ b/Kernel/TTY/PTYMultiplexer.cpp
@@ -26,9 +26,9 @@
 
 #include "PTYMultiplexer.h"
 #include "MasterPTY.h"
-#include <AK/Singleton.h>
 #include <Kernel/FileSystem/FileDescription.h>
 #include <Kernel/Process.h>
+#include <Kernel/Singleton.h>
 #include <LibC/errno_numbers.h>
 
 //#define PTMX_DEBUG
@@ -36,7 +36,7 @@
 namespace Kernel {
 
 static const unsigned s_max_pty_pairs = 8;
-static auto s_the = AK::make_singleton<PTYMultiplexer>();
+static auto s_the = make_singleton<PTYMultiplexer>();
 
 PTYMultiplexer& PTYMultiplexer::the()
 {
diff --git a/Kernel/Time/TimeManagement.cpp b/Kernel/Time/TimeManagement.cpp
index ff37fa33aafddd..7982c354b51abc 100644
--- a/Kernel/Time/TimeManagement.cpp
+++ b/Kernel/Time/TimeManagement.cpp
@@ -24,7 +24,6 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-#include <AK/Singleton.h>
 #include <Kernel/ACPI/Parser.h>
 #include <Kernel/CommandLine.h>
 #include <Kernel/Scheduler.h>
@@ -33,6 +32,7 @@
 #include <Kernel/Time/HardwareTimer.h>
 #include <Kernel/Time/PIT.h>
 #include <Kernel/Time/RTC.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/Time/TimeManagement.h>
 #include <Kernel/VM/MemoryManager.h>
 
@@ -40,7 +40,7 @@
 
 namespace Kernel {
 
-static auto s_the = AK::make_singleton<TimeManagement>();
+static auto s_the = make_singleton<TimeManagement>();
 
 TimeManagement& TimeManagement::the()
 {
diff --git a/Kernel/TimerQueue.cpp b/Kernel/TimerQueue.cpp
index d12e4ecd52a1de..41197d6861feeb 100644
--- a/Kernel/TimerQueue.cpp
+++ b/Kernel/TimerQueue.cpp
@@ -27,14 +27,14 @@
 #include <AK/Function.h>
 #include <AK/NonnullOwnPtr.h>
 #include <AK/OwnPtr.h>
-#include <AK/Singleton.h>
 #include <Kernel/Scheduler.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/Time/TimeManagement.h>
 #include <Kernel/TimerQueue.h>
 
 namespace Kernel {
 
-static auto s_the = AK::make_singleton<TimerQueue>();
+static auto s_the = make_singleton<TimerQueue>();
 
 TimerQueue& TimerQueue::the()
 {
diff --git a/Kernel/VM/MemoryManager.cpp b/Kernel/VM/MemoryManager.cpp
index 9c984de81ee44a..8280503679e9cf 100644
--- a/Kernel/VM/MemoryManager.cpp
+++ b/Kernel/VM/MemoryManager.cpp
@@ -26,7 +26,6 @@
 
 #include <AK/Assertions.h>
 #include <AK/Memory.h>
-#include <AK/Singleton.h>
 #include <AK/StringView.h>
 #include <Kernel/Arch/i386/CPU.h>
 #include <Kernel/CMOS.h>
@@ -40,6 +39,7 @@
 #include <Kernel/VM/PhysicalRegion.h>
 #include <Kernel/VM/PurgeableVMObject.h>
 #include <Kernel/VM/SharedInodeVMObject.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/StdLib.h>
 
 //#define MM_DEBUG
@@ -51,7 +51,7 @@ extern FlatPtr end_of_kernel_bss;
 
 namespace Kernel {
 
-static auto s_the = AK::make_singleton<MemoryManager>();
+static auto s_the = make_singleton<MemoryManager>();
 RecursiveSpinLock s_mm_lock;
 
 MemoryManager& MM
diff --git a/Kernel/VM/PageDirectory.cpp b/Kernel/VM/PageDirectory.cpp
index 573caa28dbc726..1b15853d94881c 100644
--- a/Kernel/VM/PageDirectory.cpp
+++ b/Kernel/VM/PageDirectory.cpp
@@ -25,9 +25,9 @@
  */
 
 #include <AK/Memory.h>
-#include <AK/Singleton.h>
 #include <Kernel/Process.h>
 #include <Kernel/Random.h>
+#include <Kernel/Singleton.h>
 #include <Kernel/Thread.h>
 #include <Kernel/VM/MemoryManager.h>
 #include <Kernel/VM/PageDirectory.h>
@@ -38,7 +38,7 @@ static const FlatPtr userspace_range_base = 0x00800000;
 static const FlatPtr userspace_range_ceiling = 0xbe000000;
 static const FlatPtr kernelspace_range_base = 0xc0800000;
 
-static auto s_cr3_map = AK::make_singleton<HashMap<u32, PageDirectory*>>();
+static auto s_cr3_map = make_singleton<HashMap<u32, PageDirectory*>>();
 
 static HashMap<u32, PageDirectory*>& cr3_map()
 {