From 7a73f824e4d4a8830e5095bd388b21c631c60c40 Mon Sep 17 00:00:00 2001
From: Anders <anders@andersha.com>
Date: Sun, 27 Nov 2016 18:38:15 +0100
Subject: [PATCH] Improved the documentation in the event delivery routine.

---
 Sources/Signal.swift | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Sources/Signal.swift b/Sources/Signal.swift
index f5b5722dc..08b9a33e8 100644
--- a/Sources/Signal.swift
+++ b/Sources/Signal.swift
@@ -134,6 +134,10 @@ public final class Signal<Value, Error: Swift.Error> {
 					if !shouldDispose && !terminated && !isTerminating, let state = interruptedState {
 						sendLock.lock()
 
+						// `terminated` before acquring the lock could be a false negative,
+						// since it might race against other concurrent senders until the
+						// lock acquisition above succeeds. So we have to check again if the
+						// signal is really still alive.
 						if !terminated {
 							interrupt(state.observers)
 							shouldDispose = true