From 8caae219cffc33d2986f2ef5ab8c7dd5e180ea36 Mon Sep 17 00:00:00 2001
From: Howard Hinnant <howard.hinnant@gmail.com>
Date: Tue, 14 Oct 2014 10:33:10 -0400
Subject: [PATCH] Gracefully cast from std::thread::hardware_concurrency

---
 src/beast/beast/module/core/thread/Workers.h |  3 ++-
 src/ripple/core/impl/JobQueue.cpp            | 14 ++------------
 2 files changed, 4 insertions(+), 13 deletions(-)

diff --git a/src/beast/beast/module/core/thread/Workers.h b/src/beast/beast/module/core/thread/Workers.h
index 0fb8daf15..0f54ca3e0 100644
--- a/src/beast/beast/module/core/thread/Workers.h
+++ b/src/beast/beast/module/core/thread/Workers.h
@@ -56,7 +56,8 @@ public:
     */
     explicit Workers (Callback& callback,
                       String const& threadNames = "Worker",
-                      int numberOfThreads = std::thread::hardware_concurrency());
+                      int numberOfThreads =
+                         static_cast<int>(std::thread::hardware_concurrency()));
 
     ~Workers ();
 
diff --git a/src/ripple/core/impl/JobQueue.cpp b/src/ripple/core/impl/JobQueue.cpp
index 50d3cd44c..f4601f128 100644
--- a/src/ripple/core/impl/JobQueue.cpp
+++ b/src/ripple/core/impl/JobQueue.cpp
@@ -226,18 +226,8 @@ public:
         }
         else if (c == 0)
         {
-            c = std::thread::hardware_concurrency();
-
-            // VFALCO NOTE According to boost, hardware_concurrency cannot return
-            //             negative numbers/
-            //
-            if (c < 0)
-                c = 2; // VFALCO NOTE Why 2?
-
-            if (c > 4) // I/O will bottleneck
-                c = 4;
-
-            c += 2;
+            c = static_cast<int>(std::thread::hardware_concurrency());
+            c = 2 + std::min (c, 4); // I/O will bottleneck
 
             m_journal.info << "Auto-tuning to " << c <<
                               " validation/transaction/proposal threads";