From 8a14a656fbd8843628b61e5a20877b40b772482c Mon Sep 17 00:00:00 2001
From: Feoramund <161657516+Feoramund@users.noreply.github.com>
Date: Mon, 9 Sep 2024 16:05:29 -0400
Subject: [PATCH] Fix `chan.can_send` for unbuffered channels

`w_waiting` is the signal that says a caller is waiting to be able to
send something. It is incremented upon send and - in the case of an
unbuffered channel - it can only hold one message.

Therefore, check that `w_waiting` is zero instead.
---
 core/sync/chan/chan.odin | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/core/sync/chan/chan.odin b/core/sync/chan/chan.odin
index f0b04f3b4..5b9a764b4 100644
--- a/core/sync/chan/chan.odin
+++ b/core/sync/chan/chan.odin
@@ -444,7 +444,7 @@ can_send :: proc "contextless" (c: ^Raw_Chan) -> bool {
 	if is_buffered(c) {
 		return c.queue.len < c.queue.cap
 	}
-	return sync.atomic_load(&c.r_waiting) > 0
+	return sync.atomic_load(&c.w_waiting) == 0
 }