WindowServer: Move the CPU monitor thingy to its own class.

Author: https://github.com/awesomekling
Commit: https://github.com/SerenityOS/serenity/commit/c2093ad9942

AK/CircularQueue.h

@@ -1,7 +1,7 @@
 #pragma once
 
-#include "Assertions.h"
-#include "Types.h"
+#include <AK/Assertions.h>
+#include <AK/Types.h>
 
 namespace AK {
 
@@ -19,15 +19,6 @@ public:
 
     int capacity() const { return Capacity; }
 
-    void dump() const
-    {
-        kprintf("CircularQueue<%zu>:\n", Capacity);
-        kprintf(" size: %zu\n", m_size);
-        for (int i = 0; i < Capacity; ++i) {
-            kprintf(" [%zu] %d %c\n", i, m_elements[i], i == m_head ? '*' : ' ');
-        }
-    }
-
     void enqueue(const T& t)
     {
         m_elements[(m_head + m_size) % Capacity] = t;

Servers/WindowServer/Makefile

@@ -24,6 +24,7 @@ WINDOWSERVER_OBJS = \
     WSCursor.o \
     WSWindowFrame.o \
     WSButton.o \
+    WSCPUMonitor.o \
     main.o
 
 APP = WindowServer

Servers/WindowServer/WSCPUMonitor.cpp

@@ -0,0 +1,74 @@
+#include <WindowServer/WSCPUMonitor.h>
+#include <WindowServer/WSMessageLoop.h>
+#include <WindowServer/WSWindowManager.h>
+#include <unistd.h>
+#include <stdio.h>
+
+WSCPUMonitor::WSCPUMonitor()
+{
+    create_thread([] (void* context) -> int {
+        auto& monitor = *(WSCPUMonitor*)context;
+        for (;;) {
+            static unsigned last_busy;
+            static unsigned last_idle;
+            unsigned busy;
+            unsigned idle;
+            monitor.get_cpu_usage(busy, idle);
+            unsigned busy_diff = busy - last_busy;
+            unsigned idle_diff = idle - last_idle;
+            last_busy = busy;
+            last_idle = idle;
+            float cpu = (float)busy_diff / (float)(busy_diff + idle_diff);
+            monitor.m_cpu_history.enqueue(cpu);
+            monitor.m_dirty = true;
+            sleep(1);
+        }
+    }, this);
+}
+
+void WSCPUMonitor::get_cpu_usage(unsigned& busy, unsigned& idle)
+{
+    busy = 0;
+    idle = 0;
+
+    FILE* fp = fopen("/proc/all", "r");
+    if (!fp) {
+        perror("failed to open /proc/all");
+        ASSERT_NOT_REACHED();
+    }
+    for (;;) {
+        char buf[BUFSIZ];
+        char* ptr = fgets(buf, sizeof(buf), fp);
+        if (!ptr)
+            break;
+        auto parts = String(buf, Chomp).split(',');
+        if (parts.size() < 17)
+            break;
+        bool ok;
+        pid_t pid = parts[0].to_uint(ok);
+        ASSERT(ok);
+        unsigned nsched = parts[1].to_uint(ok);
+        ASSERT(ok);
+
+        if (pid == 0)
+            idle += nsched;
+        else
+            busy += nsched;
+    }
+    int rc = fclose(fp);
+    ASSERT(rc == 0);
+}
+
+void WSCPUMonitor::paint(Painter& painter, const Rect& rect)
+{
+    painter.fill_rect(rect, Color::Black);
+    int i = m_cpu_history.capacity() - m_cpu_history.size();
+    for (auto cpu_usage : m_cpu_history) {
+        painter.draw_line(
+            { rect.x() + i, rect.bottom() },
+            { rect.x() + i, (int)(rect.y() + (rect.height() - (cpu_usage * (float)rect.height()))) },
+            Color::from_rgb(0xaa6d4b)
+        );
+        ++i;
+    }
+}

Servers/WindowServer/WSCPUMonitor.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#include <AK/CircularQueue.h>
+
+class Painter;
+class Rect;
+
+class WSCPUMonitor {
+public:
+    WSCPUMonitor();
+
+    bool is_dirty() const { return m_dirty; }
+    void set_dirty(bool dirty) { m_dirty = dirty; }
+    int capacity() const { return m_cpu_history.capacity(); }
+    void paint(Painter&, const Rect&);
+
+private:
+    void get_cpu_usage(unsigned& busy, unsigned& idle);
+
+    CircularQueue<float, 30> m_cpu_history;
+    bool m_dirty { false };
+};

Servers/WindowServer/WSWindowManager.cpp

@@ -22,8 +22,6 @@
 //#define DEBUG_COUNTERS
 //#define RESIZE_DEBUG
 
-static void get_cpu_usage(unsigned& busy, unsigned& idle);
-
 static WSWindowManager* s_the;
 
 WSWindowManager& WSWindowManager::the()
@@ -143,34 +141,13 @@ WSWindowManager::WSWindowManager()
     // NOTE: This ensures that the system menu has the correct dimensions.
     set_current_menubar(nullptr);
 
-    create_thread([] (void* context) -> int {
-        auto& wm = *(WSWindowManager*)context;
-        for (;;) {
-            static unsigned last_busy;
-            static unsigned last_idle;
-            unsigned busy;
-            unsigned idle;
-            get_cpu_usage(busy, idle);
-            unsigned busy_diff = busy - last_busy;
-            unsigned idle_diff = idle - last_idle;
-            last_busy = busy;
-            last_idle = idle;
-            float cpu = (float)busy_diff / (float)(busy_diff + idle_diff);
-            wm.m_cpu_history.enqueue(cpu);
-            sleep(1);
-        }
-    }, this);
-
     WSMessageLoop::the().start_timer(300, [this] {
         static time_t last_update_time;
-        static int last_cpu_history_size = 0;
-        static int last_cpu_history_head_index = 0;
         time_t now = time(nullptr);
-        if (now != last_update_time || m_cpu_history.size() != last_cpu_history_size || m_cpu_history.head_index() != last_cpu_history_head_index) {
+        if (now != last_update_time || m_cpu_monitor.is_dirty()) {
             tick_clock();
             last_update_time = now;
-            last_cpu_history_head_index = m_cpu_history.head_index();
-            last_cpu_history_size = m_cpu_history.size();
+            m_cpu_monitor.set_dirty(false);
         }
     });
 
@@ -202,39 +179,6 @@ const Font& WSWindowManager::app_menu_font() const
     return Font::default_bold_font();
 }
 
-void get_cpu_usage(unsigned& busy, unsigned& idle)
-{
-    busy = 0;
-    idle = 0;
-
-    FILE* fp = fopen("/proc/all", "r");
-    if (!fp) {
-        perror("failed to open /proc/all");
-        ASSERT_NOT_REACHED();
-    }
-    for (;;) {
-        char buf[BUFSIZ];
-        char* ptr = fgets(buf, sizeof(buf), fp);
-        if (!ptr)
-            break;
-        auto parts = String(buf, Chomp).split(',');
-        if (parts.size() < 17)
-            break;
-        bool ok;
-        pid_t pid = parts[0].to_uint(ok);
-        ASSERT(ok);
-        unsigned nsched = parts[1].to_uint(ok);
-        ASSERT(ok);
-
-        if (pid == 0)
-            idle += nsched;
-        else
-            busy += nsched;
-    }
-    int rc = fclose(fp);
-    ASSERT(rc == 0);
-}
-
 void WSWindowManager::tick_clock()
 {
     invalidate(menubar_rect());
@@ -926,17 +870,8 @@ void WSWindowManager::draw_menubar()
 
     m_back_painter->draw_text(time_rect, time_text, font(), TextAlignment::CenterRight, Color::Black);
 
-    Rect cpu_rect { time_rect.right() - font().width(time_text) - (int)m_cpu_history.capacity() - 10, time_rect.y() + 1, (int)m_cpu_history.capacity(), time_rect.height() - 2 };
-    m_back_painter->fill_rect(cpu_rect, Color::Black);
-    int i = m_cpu_history.capacity() - m_cpu_history.size();
-    for (auto cpu_usage : m_cpu_history) {
-        m_back_painter->draw_line(
-            { cpu_rect.x() + i, cpu_rect.bottom() },
-            { cpu_rect.x() + i, (int)(cpu_rect.y() + (cpu_rect.height() - (cpu_usage * (float)cpu_rect.height()))) },
-            Color::from_rgb(0xaa6d4b)
-        );
-        ++i;
-    }
+    Rect cpu_rect { time_rect.right() - font().width(time_text) - m_cpu_monitor.capacity() - 10, time_rect.y() + 1, m_cpu_monitor.capacity(), time_rect.height() - 2 };
+    m_cpu_monitor.paint(*m_back_painter, cpu_rect);
 }
 
 void WSWindowManager::draw_window_switcher()

Servers/WindowServer/WSWindowManager.h

@@ -15,7 +15,7 @@
 #include <WindowServer/WSWindow.h>
 #include <WindowServer/WSCursor.h>
 #include <WindowServer/WSMessage.h>
-#include <AK/CircularQueue.h>
+#include <WindowServer/WSCPUMonitor.h>
 
 class WSAPIClientRequest;
 class WSScreen;
@@ -216,11 +216,11 @@ private:
 
     WSWindowSwitcher m_switcher;
 
-    CircularQueue<float, 30> m_cpu_history;
-
     String m_username;
     WeakPtr<WSButton> m_cursor_tracking_button;
     WeakPtr<WSButton> m_hovered_button;
+
+    WSCPUMonitor m_cpu_monitor;
 };
 
 template<typename Callback>