From d2da33235d3a63b418097bc42812ada9696f7672 Mon Sep 17 00:00:00 2001
From: kalsprite <jon@lipstate.com>
Date: Fri, 21 Aug 2026 09:18:57 -0700
Subject: [PATCH] nbio(windows): handle queued work in the tick that was woken
 for it; nbio(tests): let wake_up tolerate a tick that returns without
 progress

---
 core/nbio/impl_windows.odin | 14 ++++++++++++++
 tests/core/nbio/nbio.odin   |  7 +++++--
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/core/nbio/impl_windows.odin b/core/nbio/impl_windows.odin
index e1e0f2ebc..7357f7c18 100644
--- a/core/nbio/impl_windows.odin
+++ b/core/nbio/impl_windows.odin
@@ -241,6 +241,20 @@ __tick :: proc(l: ^Event_Loop, timeout: time.Duration) -> (err: General_Error) {
 		actual_timeout = 0
 	}
 
+	// A wake, or another loop routing a completion to us, can leave work queued.
+	// Handle it here instead of waiting for the caller to tick again.
+	for {
+		op := (^Operation)(mpsc_dequeue(&l.queue))
+		if op == nil { break }
+		_exec(op)
+	}
+
+	for {
+		op := (^Operation)(mpsc_dequeue(&l.completed_oob))
+		if op == nil { break }
+		handle_completed(op)
+	}
+
 	return nil
 
 	compute_timeout :: proc(l: ^Event_Loop, timeout: time.Duration, next_timeout: Maybe(time.Duration)) -> win.DWORD {
diff --git a/tests/core/nbio/nbio.odin b/tests/core/nbio/nbio.odin
index 6121d1ac7..5d43fd814 100644
--- a/tests/core/nbio/nbio.odin
+++ b/tests/core/nbio/nbio.odin
@@ -244,8 +244,11 @@ wake_up :: proc(t: ^testing.T) {
 			}, context)
 			defer thread.destroy(thr)
 
-			// Should block forever until the thread calling wake_up will make it return.
-			ev(t, nbio.tick(), nil)
+			// A tick can return without progress; loop until the wake is observed.
+			// A lost wake would block here forever and trip the fail timeout.
+			for !hit {
+				ev(t, nbio.tick(), nil)
+			}
 			e(t, hit)
 
 			nbio.remove(accept)