RandomSeed.h

Go to the documentation of this file.

// Fresh execution seeds, including one shared seed for an MPI communicator.
#pragma once
#include "../Interfaces/State.h"
#ifdef __linux__
#include "../DistributedGpu/DistributedMpiGpuLibrary.h"
#endif
#include <charconv>
 
namespace Simulators
{
inline uint64_t GenerateRandomSeed(SimulatorType type, const std::unordered_map<std::string, std::string> &options = {})
{
    if (type == SimulatorType::kDistMpiGpuSim)
    {
#ifdef __linux__
        DistributedMpiGpuLibrary::Communicator descriptor{sizeof(descriptor), 0, 0};
        const auto found = options.find("mpi_communicator");
        const auto *communicator = &descriptor;
        if (found == options.end())
        {
            communicator = nullptr;
        }
        else
        {
            const auto &value = found->second;
            const auto parsed = std::from_chars(value.data(), value.data() + value.size(), descriptor.fortran_handle);
            if (parsed.ec != std::errc{} || parsed.ptr != value.data() + value.size())
                throw std::invalid_argument("Invalid MPI communicator handle");
        }
        return DistributedMpiGpuLibrary::GetInstance()->GenerateSeed(communicator);
#else
        throw std::runtime_error("MPI GPU execution requires Linux");
#endif
    }
    std::random_device entropy;
    return std::uniform_int_distribution<uint64_t>{}(entropy);
}
} // namespace Simulators