// Copyright 2009-2020 Intel Corporation // SPDX-License-Identifier: Apache-2.0 #pragma once #include "intrinsics.h" #include "sysinfo.h" #include "atomic.h" namespace embree { /*! system barrier using operating system */ class BarrierSys { public: /*! construction / destruction */ BarrierSys (size_t N = 0); ~BarrierSys (); private: /*! class in non-copyable */ BarrierSys (const BarrierSys& other) DELETED; // do not implement BarrierSys& operator= (const BarrierSys& other) DELETED; // do not implement public: /*! intializes the barrier with some number of threads */ void init(size_t count); /*! lets calling thread wait in barrier */ void wait(); private: void* opaque; }; /*! fast active barrier using atomitc counter */ struct BarrierActive { public: BarrierActive () : cntr(0) {} void reset() { cntr.store(0); } void wait (size_t numThreads) { cntr++; while (cntr.load() != numThreads) pause_cpu(); } private: std::atomic<size_t> cntr; }; /*! fast active barrier that does not require initialization to some number of threads */ struct BarrierActiveAutoReset { public: BarrierActiveAutoReset () : cntr0(0), cntr1(0) {} void wait (size_t threadCount) { cntr0.fetch_add(1); while (cntr0 != threadCount) pause_cpu(); cntr1.fetch_add(1); while (cntr1 != threadCount) pause_cpu(); cntr0.fetch_add(-1); while (cntr0 != 0) pause_cpu(); cntr1.fetch_add(-1); while (cntr1 != 0) pause_cpu(); } private: std::atomic<size_t> cntr0; std::atomic<size_t> cntr1; }; class LinearBarrierActive { public: /*! construction and destruction */ LinearBarrierActive (size_t threadCount = 0); ~LinearBarrierActive(); private: /*! class in non-copyable */ LinearBarrierActive (const LinearBarrierActive& other) DELETED; // do not implement LinearBarrierActive& operator= (const LinearBarrierActive& other) DELETED; // do not implement public: /*! intializes the barrier with some number of threads */ void init(size_t threadCount); /*! thread with threadIndex waits in the barrier */ void wait (const size_t threadIndex); private: volatile unsigned char* count0; volatile unsigned char* count1; volatile unsigned int mode; volatile unsigned int flag0; volatile unsigned int flag1; volatile size_t threadCount; }; }