From 2022a5e65ca7f1331f1864236390827a7a22c707 Mon Sep 17 00:00:00 2001
From: Jonathan White <support@dmapps.us>
Date: Tue, 7 Apr 2020 11:04:40 -0400
Subject: [PATCH] Perform one KDF benchmark at a time

* Prevent using double memory when benchmarking Argon2 performance.
* Improve benchmark results by not overusing CPU and memory simultaneously. Parallel benchmarks were causing artificially strained calculations resulting in a lower than desired number of rounds.
---
 src/crypto/kdf/Kdf.cpp | 17 ++++++++++-------
 1 file changed, 10 insertions(+), 7 deletions(-)

diff --git a/src/crypto/kdf/Kdf.cpp b/src/crypto/kdf/Kdf.cpp
index b4c4427c..6a4c7fc6 100644
--- a/src/crypto/kdf/Kdf.cpp
+++ b/src/crypto/kdf/Kdf.cpp
@@ -71,16 +71,19 @@ void Kdf::randomizeSeed()
 
 int Kdf::benchmark(int msec) const
 {
-    BenchmarkThread thread1(msec, this);
-    BenchmarkThread thread2(msec, this);
+    // Run the benchmark twice using half the time for each run
+    BenchmarkThread thread(msec / 2, this);
+    int rounds = 0;
 
-    thread1.start();
-    thread2.start();
+    thread.start();
+    thread.wait();
+    rounds += thread.rounds();
 
-    thread1.wait();
-    thread2.wait();
+    thread.start();
+    thread.wait();
+    rounds += thread.rounds();
 
-    return qMax(1, (thread1.rounds() + thread2.rounds()) / 2);
+    return qMax(1, rounds);
 }
 
 Kdf::BenchmarkThread::BenchmarkThread(int msec, const Kdf* kdf)