From 65ee020cec39db6d1dc723b19c70f694aa62c1b6 Mon Sep 17 00:00:00 2001
From: Florian Schmaus <flow@cs.fau.de>
Date: Thu, 12 Jul 2018 16:11:24 +0200
Subject: [PATCH] Add fast path to Fiber.setRunnableFalse()
---
emper/Fiber.hpp | 8 ++++++++
1 file changed, 8 insertions(+)
diff --git a/emper/Fiber.hpp b/emper/Fiber.hpp
index b49b941c..81806b23 100644
--- a/emper/Fiber.hpp
+++ b/emper/Fiber.hpp
@@ -84,6 +84,14 @@ private:
}
inline bool setRunnableFalse() {
+ bool res = runnable.load(std::memory_order_relaxed);
+ if (!res) {
+ // Fast path: 'runnable' was already set to false. No need
+ // for an atomic operation.
+ // Mesure: Impact of this "optimization". Is it really one?
+ return res;
+ }
+
return runnable.exchange(false);
}
--
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