Tear out or duplicate what's unique for WindowServer from Widgets.

This turned into a huge refactoring that somehow also includes
making locks recursive/reentrant.

Kernel/GUIEventDevice.cpp

@@ -0,0 +1,38 @@
+#include "GUIEventDevice.h"
+#include <Kernel/Process.h>
+#include <AK/Lock.h>
+#include <LibC/errno_numbers.h>
+
+//#define GUIEVENTDEVICE_DEBUG
+
+GUIEventDevice::GUIEventDevice()
+    : CharacterDevice(66, 1)
+{
+}
+
+GUIEventDevice::~GUIEventDevice()
+{
+}
+
+bool GUIEventDevice::can_read(Process& process) const
+{
+    return !process.gui_events().is_empty();
+}
+
+ssize_t GUIEventDevice::read(Process& process, byte* buffer, size_t size)
+{
+#ifdef GUIEVENTDEVICE_DEBUG
+    dbgprintf("GUIEventDevice::read(): %s<%u>, size=%u, sizeof(GUI_Event)=%u\n", process.name().characters(), process.pid(), size, sizeof(GUI_Event));
+#endif
+    if (process.gui_events().is_empty())
+        return 0;
+    LOCKER(process.gui_events_lock());
+    ASSERT(size == sizeof(GUI_Event));
+    *reinterpret_cast<GUI_Event*>(buffer) = process.gui_events().take_first();
+    return size;
+}
+
+ssize_t GUIEventDevice::write(Process&, const byte*, size_t)
+{
+    return -EINVAL;
+}

Kernel/GUIEventDevice.h

@@ -0,0 +1,16 @@
+#pragma once
+
+#include <VirtualFileSystem/CharacterDevice.h>
+
+class GUIEventDevice final : public CharacterDevice {
+public:
+    GUIEventDevice();
+    virtual ~GUIEventDevice() override;
+
+private:
+    // ^CharacterDevice
+    virtual ssize_t read(Process&, byte* buffer, size_t bufferSize) override;
+    virtual ssize_t write(Process&, const byte* buffer, size_t bufferSize) override;
+    virtual bool can_read(Process&) const override;
+    virtual bool can_write(Process&) const override { return true; }
+};

Kernel/Makefile

@@ -30,7 +30,7 @@ KERNEL_OBJS = \
        ELFLoader.o \
        KSyms.o \
        PS2MouseDevice.o \
-       WindowServer.o
+       GUIEventDevice.o
 
 VFS_OBJS = \
     ../VirtualFileSystem/DiskDevice.o \
@@ -46,21 +46,20 @@ VFS_OBJS = \
     ../VirtualFileSystem/FileDescriptor.o \
     ../VirtualFileSystem/SyntheticFileSystem.o
 
-WIDGETS_OBJS = \
-    ../Widgets/Window.o \
-    ../Widgets/Painter.o \
-    ../Widgets/WindowManager.o \
-    ../Widgets/FrameBuffer.o \
-    ../Widgets/GraphicsBitmap.o \
-    ../Widgets/Object.o \
+WINDOWSERVER_OBJS = \
     ../Widgets/Rect.o \
-    ../Widgets/Widget.o \
+    ../Widgets/Painter.o \
     ../Widgets/Font.o \
     ../Widgets/Color.o \
     ../Widgets/CharacterBitmap.o \
-    ../Widgets/EventLoop.o \
-    ../Widgets/AbstractScreen.o \
-    ../Widgets/GUIEventDevice.o \
+    ../Widgets/GraphicsBitmap.o \
+    ../WindowServer/WSEventReceiver.o \
+    ../WindowServer/WSEventLoop.o \
+    ../WindowServer/WSWindow.o \
+    ../WindowServer/WSWindowManager.o \
+    ../WindowServer/WSFrameBuffer.o \
+    ../WindowServer/WSScreen.o \
+    ../WindowServer/main.o
 
 AK_OBJS = \
     ../AK/String.o \
@@ -68,7 +67,7 @@ AK_OBJS = \
     ../AK/StringBuilder.o \
     ../AK/FileSystemPath.o
 
-OBJS = $(KERNEL_OBJS) $(VFS_OBJS) $(AK_OBJS) $(WIDGETS_OBJS)
+OBJS = $(KERNEL_OBJS) $(VFS_OBJS) $(AK_OBJS) $(WINDOWSERVER_OBJS)
 
 NASM = nasm
 KERNEL = kernel

Kernel/Process.cpp

@@ -18,7 +18,7 @@
 #include "Scheduler.h"
 #include "FIFO.h"
 #include "KSyms.h"
-#include <Widgets/Window.h>
+#include <WindowServer/WSWindow.h>
 #include "MasterPTY.h"
 
 //#define DEBUG_IO

Kernel/Process.h

@@ -19,8 +19,7 @@ class PageDirectory;
 class Region;
 class VMObject;
 class Zone;
-class Window;
-class Widget;
+class WSWindow;
 
 #define COOL_GLOBALS
 #ifdef COOL_GLOBALS
@@ -47,7 +46,7 @@ struct DisplayInfo {
 
 class Process : public InlineLinkedListNode<Process> {
     friend class InlineLinkedListNode<Process>;
-    friend class WindowManager; // FIXME: Make a better API for allocate_region().
+    friend class WSWindowManager; // FIXME: Make a better API for allocate_region().
     friend class GraphicsBitmap; // FIXME: Make a better API for allocate_region().
 public:
     static Process* create_kernel_process(String&& name, void (*entry)());
@@ -353,7 +352,7 @@ private:
 
     RetainPtr<Region> m_display_framebuffer_region;
 
-    HashMap<int, OwnPtr<Window>> m_windows;
+    HashMap<int, OwnPtr<WSWindow>> m_windows;
 
     Vector<GUI_Event> m_gui_events;
     SpinLock m_gui_events_lock;

Kernel/ProcessGUI.cpp

@@ -1,25 +1,22 @@
 #include "Process.h"
 #include "MemoryManager.h"
 #include <LibC/errno_numbers.h>
-#include <Widgets/AbstractScreen.h>
-#include <Widgets/FrameBuffer.h>
-#include <Widgets/EventLoop.h>
 #include <Widgets/Font.h>
-#include <Widgets/Button.h>
-#include <Widgets/Label.h>
-#include <Widgets/Widget.h>
-#include <Widgets/Window.h>
-#include <Widgets/WindowManager.h>
+#include <WindowServer/WSScreen.h>
+#include <WindowServer/WSFrameBuffer.h>
+#include <WindowServer/WSEventLoop.h>
+#include <WindowServer/WSWindow.h>
+#include <WindowServer/WSWindowManager.h>
 
 void Process::initialize_gui_statics()
 {
     Font::initialize();
-    FrameBuffer::initialize();
-    EventLoop::initialize();
-    WindowManager::initialize();
-    AbstractScreen::initialize();
+    WSFrameBuffer::initialize();
+    WSEventLoop::initialize();
+    WSWindowManager::initialize();
+    WSScreen::initialize();
 
-    new EventLoop;
+    new WSEventLoop;
 }
 
 int Process::make_window_id()
@@ -36,7 +33,7 @@ int Process::make_window_id()
 static void wait_for_gui_server()
 {
     // FIXME: Time out after a while and return an error.
-    while (!EventLoop::main().running())
+    while (!WSEventLoop::the().running())
         sleep(10);
 }
 
@@ -53,13 +50,13 @@ int Process::gui$create_window(const GUI_CreateWindowParameters* user_params)
     if (rect.is_empty())
         return -EINVAL;
 
-    ProcessPagingScope scope(EventLoop::main().server_process());
+    ProcessPagingScope scope(WSEventLoop::the().server_process());
 
     int window_id = make_window_id();
     if (!window_id)
         return -ENOMEM;
 
-    auto window = make<Window>(*this, window_id);
+    auto window = make<WSWindow>(*this, window_id);
     if (!window)
         return -ENOMEM;
 
@@ -113,7 +110,6 @@ int Process::gui$invalidate_window(int window_id)
     auto& window = *(*it).value;
     // FIXME: This should queue up a message that the window server process can read.
     //        Poking into its data structures is not good.
-    InterruptDisabler disabler;
-    WindowManager::the().invalidate(window);
+    WSEventLoop::the().post_event(&window, make<WSEvent>(WSEvent::WM_Invalidate));
     return 0;
 }

Kernel/Scheduler.cpp

@@ -133,7 +133,7 @@ bool Scheduler::pick_next()
     for (auto* process = g_processes->head(); process; process = process->next()) {
         //if (process->state() == Process::BlockedWait || process->state() == Process::BlockedSleep)
 //            continue;
-        dbgprintf("% 12s %s(%u) @ %w:%x\n", toString(process->state()), process->name().characters(), process->pid(), process->tss().cs, process->tss().eip);
+        dbgprintf("[K%x] % 12s %s(%u) @ %w:%x\n", process, toString(process->state()), process->name().characters(), process->pid(), process->tss().cs, process->tss().eip);
     }
 #endif
 

Kernel/WindowServer.cpp

@@ -1,22 +0,0 @@
-#include "Process.h"
-#include <Widgets/Font.h>
-#include <Widgets/FrameBuffer.h>
-#include <Widgets/WindowManager.h>
-#include <Widgets/EventLoop.h>
-#include <Widgets/Window.h>
-
-void WindowServer_main()
-{
-    auto info = current->get_display_info();
-
-    dbgprintf("Screen is %ux%ux%ubpp\n", info.width, info.height, info.bpp);
-
-    FrameBuffer framebuffer((dword*)info.framebuffer, info.width, info.height);
-
-    WindowManager::the();
-
-    dbgprintf("Entering WindowServer main loop.\n");
-    EventLoop::main().exec();
-
-    ASSERT_NOT_REACHED();
-}

Kernel/i386.h

@@ -81,6 +81,7 @@ void write_gdt_entry(word selector, Descriptor&);
 
 #define cli() asm volatile("cli")
 #define sti() asm volatile("sti")
+#define memory_barrier() asm volatile ("" ::: "memory")
 
 static inline dword cpu_flags()
 {

Kernel/init.cpp

@@ -15,7 +15,7 @@
 #include <VirtualFileSystem/RandomDevice.h>
 #include <VirtualFileSystem/Ext2FileSystem.h>
 #include <VirtualFileSystem/VirtualFileSystem.h>
-#include <Widgets/GUIEventDevice.h>
+#include "GUIEventDevice.h"
 #include "MemoryManager.h"
 #include "ProcFileSystem.h"
 #include "RTC.h"