/*
All modification made by Intel Corporation: © 2016 Intel Corporation

All contributions by the University of California:
Copyright (c) 2014, 2015, The Regents of the University of California (Regents)
All rights reserved.

All other contributions:
Copyright (c) 2014, 2015, the respective contributors
All rights reserved.
For the list of contributors go to https://github.com/BVLC/caffe/blob/master/CONTRIBUTORS.md


Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions are met:

    * Redistributions of source code must retain the above copyright notice,
      this list of conditions and the following disclaimer.
    * Redistributions in binary form must reproduce the above copyright
      notice, this list of conditions and the following disclaimer in the
      documentation and/or other materials provided with the distribution.
    * Neither the name of Intel Corporation nor the names of its contributors
      may be used to endorse or promote products derived from this software
      without specific prior written permission.

THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#include <boost/thread.hpp>
#include <glog/logging.h>
#include <cmath>
#include <cstdio>
#include <ctime>

#if defined(_MSC_EXTENSIONS)
#include <process.h>
#define getpid() _getpid()
#endif

#include "caffe/common.hpp"
#include "caffe/util/rng.hpp"

#ifdef _OPENMP
#include <omp.h>
#endif

namespace caffe {

// Make sure each thread can have different values.
static boost::thread_specific_ptr<Caffe> thread_instance_;

Caffe& Caffe::Get() {
  if (!thread_instance_.get()) {
    thread_instance_.reset(new Caffe());
  }
  return *(thread_instance_.get());
}

// random seeding
int64_t cluster_seedgen(void) {
#ifdef DETERMINISTIC
  return 4013;
#else
  int64_t s, seed, pid;
  FILE* f = fopen("/dev/urandom", "rb");
  if (f && fread(&seed, 1, sizeof(seed), f) == sizeof(seed)) {
    fclose(f);
    return seed;
  }

  LOG(INFO) << "System entropy source not available, "
              "using fallback algorithm to generate seed instead.";
  if (f)
    fclose(f);

  pid = getpid();
  s = time(NULL);
  seed = std::abs(((s * 181) * ((pid - 83) * 359)) % 104729);
  return seed;
#endif
}


void GlobalInit(int* pargc, char*** pargv) {
  // Google flags.
  ::gflags::ParseCommandLineFlags(pargc, pargv, true);
  // Google logging.
  ::google::InitGoogleLogging(*(pargv)[0]);
  // Provide a backtrace on segfault.
  ::google::InstallFailureSignalHandler();
}

#ifdef CPU_ONLY  // CPU-only Caffe.

Caffe::Caffe()
    : random_generator_(), mode_(Caffe::CPU),
      solver_count_(1), root_solver_(true), iter_size_(1) { }

Caffe::~Caffe() { }

void Caffe::set_random_seed(const unsigned int seed) {
  // RNG seed
  Get().random_generator_.reset(new RNG(seed));
}

void Caffe::SetDevice(const int device_id) {
  NO_GPU;
}

void Caffe::DeviceQuery() {
  NO_GPU;
}

bool Caffe::CheckDevice(const int device_id) {
  NO_GPU;
  return false;
}

int Caffe::FindDevice(const int start_id) {
  NO_GPU;
  return -1;
}

class Caffe::RNG::Generator {
 public:
  Generator() : rng_(new caffe::rng_t(cluster_seedgen())) {}
  explicit Generator(unsigned int seed) : rng_(new caffe::rng_t(seed)) {}
  caffe::rng_t* rng() { return rng_.get(); }
 private:
  shared_ptr<caffe::rng_t> rng_;
};

Caffe::RNG::RNG() : generator_(new Generator()) { }

Caffe::RNG::RNG(unsigned int seed) : generator_(new Generator(seed)) { }

Caffe::RNG& Caffe::RNG::operator=(const RNG& other) {
  generator_ = other.generator_;
  return *this;
}

void* Caffe::RNG::generator() {
  return static_cast<void*>(generator_->rng());
}

#else  // Normal GPU + CPU Caffe.

Caffe::Caffe()
    : cublas_handle_(NULL), curand_generator_(NULL), random_generator_(),
    mode_(Caffe::CPU), solver_count_(1), root_solver_(true), iter_size_(1) {
  // Try to create a cublas handler, and report an error if failed (but we will
  // keep the program running as one might just want to run CPU code).
  if (cublasCreate(&cublas_handle_) != CUBLAS_STATUS_SUCCESS) {
    LOG(ERROR) << "Cannot create Cublas handle. Cublas won't be available.";
  }
  // Try to create a curand handler.
  if (curandCreateGenerator(&curand_generator_, CURAND_RNG_PSEUDO_DEFAULT)
      != CURAND_STATUS_SUCCESS ||
      curandSetPseudoRandomGeneratorSeed(curand_generator_, cluster_seedgen())
      != CURAND_STATUS_SUCCESS) {
    LOG(ERROR) << "Cannot create Curand generator. Curand won't be available.";
  }
}

Caffe::~Caffe() {
#ifdef _OPENMP
  if (0 == omp_get_thread_num()) {
#endif
  if (cublas_handle_) CUBLAS_CHECK(cublasDestroy(cublas_handle_));
  if (curand_generator_) {
    CURAND_CHECK(curandDestroyGenerator(curand_generator_));
  }
#ifdef _OPENMP
  }
#endif
}

void Caffe::set_random_seed(const unsigned int seed) {
  // Curand seed
  static bool g_curand_availability_logged = false;
  if (Get().curand_generator_) {
    CURAND_CHECK(curandSetPseudoRandomGeneratorSeed(curand_generator(),
        seed));
    CURAND_CHECK(curandSetGeneratorOffset(curand_generator(), 0));
  } else {
    if (!g_curand_availability_logged) {
        LOG(ERROR) <<
            "Curand not available. Skipping setting the curand seed.";
        g_curand_availability_logged = true;
    }
  }
  // RNG seed
  Get().random_generator_.reset(new RNG(seed));
}

void Caffe::SetDevice(const int device_id) {
  int current_device;
  CUDA_CHECK(cudaGetDevice(&current_device));
  if (current_device == device_id) {
    return;
  }
  // The call to cudaSetDevice must come before any calls to Get, which
  // may perform initialization using the GPU.
  CUDA_CHECK(cudaSetDevice(device_id));
  if (Get().cublas_handle_) CUBLAS_CHECK(cublasDestroy(Get().cublas_handle_));
  if (Get().curand_generator_) {
    CURAND_CHECK(curandDestroyGenerator(Get().curand_generator_));
  }
  CUBLAS_CHECK(cublasCreate(&Get().cublas_handle_));
  CURAND_CHECK(curandCreateGenerator(&Get().curand_generator_,
      CURAND_RNG_PSEUDO_DEFAULT));
  CURAND_CHECK(curandSetPseudoRandomGeneratorSeed(Get().curand_generator_,
      cluster_seedgen()));
}

void Caffe::DeviceQuery() {
  cudaDeviceProp prop;
  int device;
  if (cudaSuccess != cudaGetDevice(&device)) {
    printf("No cuda device present.\n");
    return;
  }
  CUDA_CHECK(cudaGetDeviceProperties(&prop, device));
  LOG(INFO) << "Device id:                     " << device;
  LOG(INFO) << "Major revision number:         " << prop.major;
  LOG(INFO) << "Minor revision number:         " << prop.minor;
  LOG(INFO) << "Name:                          " << prop.name;
  LOG(INFO) << "Total global memory:           " << prop.totalGlobalMem;
  LOG(INFO) << "Total shared memory per block: " << prop.sharedMemPerBlock;
  LOG(INFO) << "Total registers per block:     " << prop.regsPerBlock;
  LOG(INFO) << "Warp size:                     " << prop.warpSize;
  LOG(INFO) << "Maximum memory pitch:          " << prop.memPitch;
  LOG(INFO) << "Maximum threads per block:     " << prop.maxThreadsPerBlock;
  LOG(INFO) << "Maximum dimension of block:    "
      << prop.maxThreadsDim[0] << ", " << prop.maxThreadsDim[1] << ", "
      << prop.maxThreadsDim[2];
  LOG(INFO) << "Maximum dimension of grid:     "
      << prop.maxGridSize[0] << ", " << prop.maxGridSize[1] << ", "
      << prop.maxGridSize[2];
  LOG(INFO) << "Clock rate:                    " << prop.clockRate;
  LOG(INFO) << "Total constant memory:         " << prop.totalConstMem;
  LOG(INFO) << "Texture alignment:             " << prop.textureAlignment;
  LOG(INFO) << "Concurrent copy and execution: "
      << (prop.deviceOverlap ? "Yes" : "No");
  LOG(INFO) << "Number of multiprocessors:     " << prop.multiProcessorCount;
  LOG(INFO) << "Kernel execution timeout:      "
      << (prop.kernelExecTimeoutEnabled ? "Yes" : "No");
  return;
}

bool Caffe::CheckDevice(const int device_id) {
  // This function checks the availability of GPU #device_id.
  // It attempts to create a context on the device by calling cudaFree(0).
  // cudaSetDevice() alone is not sufficient to check the availability.
  // It lazily records device_id, however, does not initialize a
  // context. So it does not know if the host thread has the permission to use
  // the device or not.
  //
  // In a shared environment where the devices are set to EXCLUSIVE_PROCESS
  // or EXCLUSIVE_THREAD mode, cudaSetDevice() returns cudaSuccess
  // even if the device is exclusively occupied by another process or thread.
  // Cuda operations that initialize the context are needed to check
  // the permission. cudaFree(0) is one of those with no side effect,
  // except the context initialization.
  bool r = ((cudaSuccess == cudaSetDevice(device_id)) &&
            (cudaSuccess == cudaFree(0)));
  // reset any error that may have occurred.
  cudaGetLastError();
  return r;
}

int Caffe::FindDevice(const int start_id) {
  // This function finds the first available device by checking devices with
  // ordinal from start_id to the highest available value. In the
  // EXCLUSIVE_PROCESS or EXCLUSIVE_THREAD mode, if it succeeds, it also
  // claims the device due to the initialization of the context.
  int count = 0;
  CUDA_CHECK(cudaGetDeviceCount(&count));
  for (int i = start_id; i < count; i++) {
    if (CheckDevice(i)) return i;
  }
  return -1;
}

class Caffe::RNG::Generator {
 public:
  Generator() : rng_(new caffe::rng_t(cluster_seedgen())) {}
  explicit Generator(unsigned int seed) : rng_(new caffe::rng_t(seed)) {}
  caffe::rng_t* rng() { return rng_.get(); }
 private:
  shared_ptr<caffe::rng_t> rng_;
};

Caffe::RNG::RNG() : generator_(new Generator()) { }

Caffe::RNG::RNG(unsigned int seed) : generator_(new Generator(seed)) { }

Caffe::RNG& Caffe::RNG::operator=(const RNG& other) {
  generator_.reset(other.generator_.get());
  return *this;
}

void* Caffe::RNG::generator() {
  return static_cast<void*>(generator_->rng());
}

const char* cublasGetErrorString(cublasStatus_t error) {
  switch (error) {
  case CUBLAS_STATUS_SUCCESS:
    return "CUBLAS_STATUS_SUCCESS";
  case CUBLAS_STATUS_NOT_INITIALIZED:
    return "CUBLAS_STATUS_NOT_INITIALIZED";
  case CUBLAS_STATUS_ALLOC_FAILED:
    return "CUBLAS_STATUS_ALLOC_FAILED";
  case CUBLAS_STATUS_INVALID_VALUE:
    return "CUBLAS_STATUS_INVALID_VALUE";
  case CUBLAS_STATUS_ARCH_MISMATCH:
    return "CUBLAS_STATUS_ARCH_MISMATCH";
  case CUBLAS_STATUS_MAPPING_ERROR:
    return "CUBLAS_STATUS_MAPPING_ERROR";
  case CUBLAS_STATUS_EXECUTION_FAILED:
    return "CUBLAS_STATUS_EXECUTION_FAILED";
  case CUBLAS_STATUS_INTERNAL_ERROR:
    return "CUBLAS_STATUS_INTERNAL_ERROR";
#if CUDA_VERSION >= 6000
  case CUBLAS_STATUS_NOT_SUPPORTED:
    return "CUBLAS_STATUS_NOT_SUPPORTED";
#endif
#if CUDA_VERSION >= 6050
  case CUBLAS_STATUS_LICENSE_ERROR:
    return "CUBLAS_STATUS_LICENSE_ERROR";
#endif
  }
  return "Unknown cublas status";
}

const char* curandGetErrorString(curandStatus_t error) {
  switch (error) {
  case CURAND_STATUS_SUCCESS:
    return "CURAND_STATUS_SUCCESS";
  case CURAND_STATUS_VERSION_MISMATCH:
    return "CURAND_STATUS_VERSION_MISMATCH";
  case CURAND_STATUS_NOT_INITIALIZED:
    return "CURAND_STATUS_NOT_INITIALIZED";
  case CURAND_STATUS_ALLOCATION_FAILED:
    return "CURAND_STATUS_ALLOCATION_FAILED";
  case CURAND_STATUS_TYPE_ERROR:
    return "CURAND_STATUS_TYPE_ERROR";
  case CURAND_STATUS_OUT_OF_RANGE:
    return "CURAND_STATUS_OUT_OF_RANGE";
  case CURAND_STATUS_LENGTH_NOT_MULTIPLE:
    return "CURAND_STATUS_LENGTH_NOT_MULTIPLE";
  case CURAND_STATUS_DOUBLE_PRECISION_REQUIRED:
    return "CURAND_STATUS_DOUBLE_PRECISION_REQUIRED";
  case CURAND_STATUS_LAUNCH_FAILURE:
    return "CURAND_STATUS_LAUNCH_FAILURE";
  case CURAND_STATUS_PREEXISTING_FAILURE:
    return "CURAND_STATUS_PREEXISTING_FAILURE";
  case CURAND_STATUS_INITIALIZATION_FAILED:
    return "CURAND_STATUS_INITIALIZATION_FAILED";
  case CURAND_STATUS_ARCH_MISMATCH:
    return "CURAND_STATUS_ARCH_MISMATCH";
  case CURAND_STATUS_INTERNAL_ERROR:
    return "CURAND_STATUS_INTERNAL_ERROR";
  }
  return "Unknown curand status";
}

#endif  // CPU_ONLY

}  // namespace caffe
