+const size_t MAX_THREADS = 128;
+const size_t MAX_SPLITPOINTS_PER_THREAD = 8;
+const size_t MAX_SLAVES_PER_SPLITPOINT = 4;
+
+class Spinlock {
+ std::atomic_int _lock;
+
+public:
+ Spinlock() { _lock = 1; } // Init here to workaround a bug with MSVC 2013
+ void lock() {
+ while (_lock.fetch_sub(1, std::memory_order_acquire) != 1)
+ for (int cnt = 0; _lock.load(std::memory_order_relaxed) <= 0; ++cnt)
+ if (cnt >= 10000) std::this_thread::yield(); // Be nice to hyperthreading
+ }
+ void unlock() { _lock.store(1, std::memory_order_release); }
+};
+