process: Add basic scheduler

1 files changed, 12 insertions, 1 deletions

diff --git a/src/process.zig b/src/process.zig
index 7070ff2..a343cd6 100644
--- a/src/process.zig
+++ b/src/process.zig
@@ -10,6 +10,8 @@ const paging = @import("paging.zig");
 const num_stack_pages = 2;
 
 var next_pid = 1;
+var previous_scheduled = 1;
+var list = std.mem.zeroInit(std.DoublyLinkedList(Info));
 
 pub const State = enum {
     waiting,
@@ -33,7 +35,7 @@ pub const Info = extern struct {
     }
 };
 
-pub fn new(entry: *fn() void) !Info {
+fn new(entry: *fn() void) !Info {
     const stack = try paging.alloc(num_stack_pages);
     errdefer paging.free(stack);
 
@@ -61,3 +63,12 @@ pub fn new(entry: *fn() void) !Info {
         try procmem.map(vaddr, paddr, paging.EntryFlags.userReadWrite, 0);
     }
 }
+
+pub fn nextScheduled() ?Info {
+    if (list.popFirst()) |next| {
+        list.append(next);
+        return next.data;
+    }
+
+    return null;
+}