Preparation for #1.4.0 (#30)

- Fixed CPU affinity on Windows for NUMA and CPUs with lot of cores
- Implemented per thread configurable Multihash mode (double, triple, quadruple, quintuple)
- Rebased from XMRig 2.4.4

src/Mem.h

@@ -5,6 +5,8 @@
  * Copyright 2014-2016 Wolf9466    <https://github.com/OhGodAPet>
  * Copyright 2016      Jay D Dee   <jayddee246@gmail.com>
  * Copyright 2016-2017 XMRig       <support@xmrig.com>
+ * Copyright 2018      Sebastian Stolzenberg <https://github.com/sebastianstolzenberg>
+ * Copyright 2018      BenDroid    <ben@graef.in>
  *
  *
  *   This program is free software: you can redistribute it and/or modify
@@ -25,8 +27,9 @@
 #define __MEM_H__
 
 
-#include <stddef.h>
-#include <stdint.h>
+#include <cstddef>
+#include <cstdint>
+#include <bitset>
 
 #include "align.h"
 #include "Options.h"
@@ -37,6 +40,7 @@ struct cryptonight_ctx;
 class Mem
 {
 public:
+    typedef std::bitset<64> ThreadBitSet;
     enum Flags {
         HugepagesAvailable = 1,
         HugepagesEnabled   = 2,
@@ -47,18 +51,23 @@ public:
     static cryptonight_ctx *create(int threadId);
     static void release();
 
-    static inline bool isDoubleHash(int threadId) { return m_doubleHash && (m_doubleHashThreadMask == -1L || ((m_doubleHashThreadMask >> threadId) & 1)); }
+    static inline size_t hashFactor()         { return m_hashFactor; }
+    static inline size_t getThreadHashFactor(int threadId)
+    {
+        return (m_multiHashThreadMask.all() ||
+                m_multiHashThreadMask.test(threadId)) ? m_hashFactor : 1;
+    }
     static inline bool isHugepagesAvailable() { return (m_flags & HugepagesAvailable) != 0; }
     static inline bool isHugepagesEnabled()   { return (m_flags & HugepagesEnabled) != 0; }
     static inline int flags()                 { return m_flags; }
-    static inline int threads()               { return m_threads; }
+    static inline size_t threads()            { return m_threads; }
 
 private:
-    static bool m_doubleHash;
+    static size_t m_hashFactor;
+    static size_t m_threads;
     static int m_algo;
     static int m_flags;
-    static int m_threads;
-    static int64_t m_doubleHashThreadMask;
+    static ThreadBitSet m_multiHashThreadMask;
     static size_t m_memorySize;
     VAR_ALIGN(16, static uint8_t *m_memory);
 };