ex: add enqueue_in to workqueue

src/ex/root.zig

@@ -8,6 +8,7 @@ pub const Console = p.console.Console;
 
 pub const workqueue = struct {
     pub const enqueue = p.workqueue.enqueue;
+    pub const enqueue_in = p.workqueue.enqueue_in;
 };
 
 pub const console = struct {

src/ex/workqueue.zig

@@ -20,6 +20,8 @@ pub const WorkItem = struct {
     link: rtl.List.Entry,
     enqueued: std.atomic.Value(bool),
     priority: Priority,
+    dpc: ke.Dpc,
+    timer: ke.Timer,
 
     pub const Priority = enum {
         /// Low priority background work.
@@ -45,7 +47,11 @@ pub const WorkItem = struct {
             .link = undefined,
             .enqueued = .init(false),
             .priority = priority,
+            .dpc = .init(work_dpc),
+            .timer = undefined,
         };
+
+        self.timer.init();
     }
 };
 
@@ -116,6 +122,17 @@ fn work_loop(p: ?*anyopaque) void {
     }
 }
 
+/// Called when a work timer expires.
+fn work_dpc(dpc: *ke.Dpc, _: ?*anyopaque) void {
+    const item: *WorkItem = @fieldParentPtr("dpc", dpc);
+    enqueue(item);
+}
+
+/// Enqueue a work item in `time`.
+pub fn enqueue_in(item: *WorkItem, time: r.Nanoseconds) void {
+    ke.timer.set(&item.timer, time, &item.dpc);
+}
+
 /// Enqueue a work item to be executed eventually.
 pub fn enqueue(item: *WorkItem) void {
     // Ensure CPU stays consistent.