From 27e6f2684b7b43710c36853258938c58c8c60a8f Mon Sep 17 00:00:00 2001
From: Jack Halford <jack@0x5.be>
Date: Sun, 15 Dec 2019 11:14:10 +0100
Subject: [PATCH] Step 3: time_used

---
 src/console.zig |  1 -
 src/main.zig    |  6 ++----
 src/task.zig    | 28 ++++++++++++----------------
 src/time.zig    | 11 +++++------
 src/vga.zig     | 12 ++++++------
 5 files changed, 25 insertions(+), 33 deletions(-)

diff --git a/src/console.zig b/src/console.zig
index 369bd84..13e9e91 100644
--- a/src/console.zig
+++ b/src/console.zig
@@ -15,7 +15,6 @@ fn execute(input: []u8) void {
     if (eql(u8, input, "tasks")) return task.introspect();
     if (eql(u8, input, "lspci")) return pci.lspci();
     if (eql(u8, input, "uptime")) return time.uptime();
-    if (eql(u8, input, "topbar")) return topbar();
     println("{}: command not found", input);
 }
 
diff --git a/src/main.zig b/src/main.zig
index 82cf7a0..0145594 100644
--- a/src/main.zig
+++ b/src/main.zig
@@ -26,9 +26,7 @@ export fn kmain(magic: u32, info: *const multiboot.MultibootInfo) noreturn {
     pci.scan();
 
     task.new(@ptrToInt(topbar)) catch unreachable;
-    // task.new(@ptrToInt(console.loop)) catch unreachable;
+    task.new(@ptrToInt(console.loop)) catch unreachable;
 
-    // task.schedule();
-    console.loop();
-    while (true) asm volatile ("hlt");
+    while (true) task.schedule();
 }
diff --git a/src/task.zig b/src/task.zig
index 281eba3..d9c1b47 100644
--- a/src/task.zig
+++ b/src/task.zig
@@ -1,5 +1,6 @@
 pub usingnamespace @import("index.zig");
 
+var timer_last_count: u64 = 0;
 var boot_task = Task{ .tid = 0, .esp = 0x47 };
 const ListOfTasks = std.TailQueue(*Task);
 var first_task = ListOfTasks.Node.init(&boot_task);
@@ -16,9 +17,17 @@ var tid_counter: u16 = 1;
 ///ASM
 extern fn switch_tasks(new_esp: u32, old_esp_addr: u32) void;
 
+pub fn update_time_used() void {
+    const current_count = time.offset_us;
+    const elapsed = current_count - timer_last_count;
+    timer_last_count = current_count;
+    current_task.data.time_used += elapsed;
+}
+
 pub const Task = packed struct {
     esp: usize,
     tid: u16,
+    time_used: u64 = 0,
     //context: isr.Context,
     //cr3: usize,
 
@@ -26,6 +35,7 @@ pub const Task = packed struct {
         // Allocate and initialize the thread structure.
         var t = try vmem.create(Task);
 
+        t.time_used = 0;
         t.tid = tid_counter;
         tid_counter +%= 1;
         assert(tid_counter != 0); //overflow
@@ -49,15 +59,9 @@ pub const Task = packed struct {
 };
 
 pub fn new(entrypoint: usize) !void {
-    // println("currently: {}", current_task.data.tid);
-    // println("first: {}", tasks.first.?.data.tid);
-    // println("last: {}", tasks.last.?.data.tid);
     const node = try vmem.create(ListOfTasks.Node);
     node.data = try Task.create(entrypoint);
     tasks.append(node);
-    // println("currently: {}", current_task.data.tid);
-    // println("first: {}", tasks.first.?.data.tid);
-    // println("last: {}", tasks.last.?.data.tid);
 }
 
 pub fn switch_to(new_task: *ListOfTasks.Node) void {
@@ -72,26 +76,18 @@ pub fn switch_to(new_task: *ListOfTasks.Node) void {
 }
 
 pub fn schedule() void {
-    // println("currently: {}", current_task.data.tid);
-    // println("first: {}", tasks.first.?.data.tid);
-    // println("last: {}", tasks.last.?.data.tid);
+    update_time_used();
     if (current_task.next) |next| {
-        // println("switching to {}", next.data.tid);
         switch_to(next);
     } else if (tasks.first) |head| {
-        // println("switching to {}", head.data.tid);
         if (head.data != current_task.data) switch_to(head);
-    } else {
-        introspect();
     }
-    // if (current_task.data.tid == 0) switch_to(tasks.last.?.*);
-    // if (current_task.data.tid == 1) switch_to(tasks.first.?.*);
-    // if (current_task.tid == 2) tasks[0].?.switch_to();
 }
 
 pub fn introspect() void {
     var it = tasks.first;
     println("{} tasks", tasks.len);
+    update_time_used();
     while (it) |node| : (it = node.next) {
         if (node.data != current_task.data) println("{}", node.data);
         if (node.data == current_task.data) println("*{}", node.data);
diff --git a/src/time.zig b/src/time.zig
index 834205c..f75b92f 100644
--- a/src/time.zig
+++ b/src/time.zig
@@ -1,14 +1,13 @@
 usingnamespace @import("index.zig");
 
-pub var offset_s: u32 = 0;
-pub var offset_us: u32 = 0;
+pub var offset_us: u64 = 0;
 pub fn increment(value: u32) void {
-    const sum = offset_us + value;
-    offset_s += sum / 1000000;
-    offset_us = sum % 1000000;
+    offset_us += value;
 }
 
 pub fn uptime() void {
-    const offset_ms = offset_us / 1000;
+    var offset_ms: u64 = offset_us / 1000;
+    const offset_s: u64 = offset_ms / 1000;
+    offset_ms = @mod(offset_ms, 1000);
     println("{}.{:.3}", offset_s, offset_ms);
 }
diff --git a/src/vga.zig b/src/vga.zig
index ecf1349..5aee204 100644
--- a/src/vga.zig
+++ b/src/vga.zig
@@ -68,9 +68,11 @@ pub fn topbar() void {
         const cursor = vga.cursor;
         vga.cursor = 0;
         vga.background = Color.Red;
+        vga.cursor_enabled = false;
 
         time.uptime();
 
+        vga.cursor_enabled = true;
         vga.cursor = cursor;
         vga.background = bg;
         task.schedule();
@@ -85,6 +87,7 @@ fn printCallback(context: void, string: []const u8) Errors!void {
 const VGA = struct {
     vram: []VGAEntry,
     cursor: usize,
+    cursor_enabled: bool = true,
     foreground: Color,
     background: Color,
 
@@ -132,7 +135,7 @@ const VGA = struct {
                 self.cursor += 1;
             },
         }
-        self.updateCursor();
+        if (self.cursor_enabled) self.updateCursor();
     }
 
     ////
@@ -142,11 +145,8 @@ const VGA = struct {
     //     string: String to be printed.
     //
     pub fn writeString(self: *VGA, string: []const u8) void {
-        for (string) |char| {
-            self.writeChar(char);
-        }
-
-        self.updateCursor();
+        for (string) |char| self.writeChar(char);
+        if (self.cursor_enabled) self.updateCursor();
     }
 
     ////