ShmSystemV.cpp

/*
 * Distributed under the OSI-approved Apache License, Version 2.0.  See
 * accompanying file Copyright.txt for details.
 *
 * ShmSystemV.cpp
 *
 *  Created on: Dec 22, 2016
 *      Author: wfg
 */
/// \cond EXCLUDE_FROM_DOXYGEN
#include <sys/shm.h>

#include <ios> //std::ios_base::failure
#include <utility>
/// \endcond

#include "ShmSystemV.h"

namespace adios
{

ShmSystemV::ShmSystemV(std::string accessMode, int rankMPI,
                       const std::string &pathName, size_t dataSize,
                       size_t metadataSize, bool debugMode)
: Capsule{"ShmSystemV", std::move(accessMode), rankMPI, debugMode},
  m_DataSize{dataSize}, m_MetadataSize{metadataSize}
{
    // Data Shared memory sector
    const std::string dataPath(pathName + "/adios.shm.data." +
                               std::to_string(m_RankMPI));
    m_DataKey = ftok(dataPath.c_str(), m_RankMPI + 1);
    m_DataShmID = shmget(m_DataKey, m_DataSize, IPC_CREAT | 0666);
    m_Data = static_cast<char *>(shmat(m_DataShmID, nullptr, 0));

    // Metadata Shared memory sector
    const std::string metadataPath(pathName + "/adios.shm.metadata." +
                                   std::to_string(m_RankMPI));
    m_MetadataKey =
        ftok(metadataPath.c_str(),
             m_RankMPI + 1); // 2nd field must be greater than zero and unique
    m_MetadataShmID = shmget(m_MetadataKey, m_MetadataSize, IPC_CREAT | 0666);
    m_Metadata = static_cast<char *>(shmat(m_MetadataShmID, nullptr, 0));

    if (m_DebugMode == true)
    {
        CheckShm();
    }
}

char *ShmSystemV::GetData() { return m_Data; }

char *ShmSystemV::GetMetadata() { return m_Metadata; }

size_t ShmSystemV::GetDataSize() const { return m_DataSize; }

size_t ShmSystemV::GetMetadataSize() const { return m_MetadataSize; }

void ShmSystemV::CheckShm() const
{
    if (m_DataShmID < 0)
    {
        throw std::ios_base::failure(
            "ERROR: Failed to create data shm segment of size " +
            std::to_string(m_DataSize) +
            " from call to ShmSystemV constructor\n");
    }

    if (m_Data == nullptr)
    {
        throw std::ios_base::failure(
            "ERROR: Failed to attach to data shm segment of size " +
            std::to_string(m_DataSize) + " and id " +
            std::to_string(m_DataShmID) +
            ", from call to ShmSystemV constructor\n");
    }

    if (m_DataShmID < 0)
    {
        throw std::ios_base::failure(
            "ERROR: Failed to create metadata shm segment of size " +
            std::to_string(m_MetadataSize) +
            " from call to ShmSystemV constructor\n");
    }

    if (m_Metadata == nullptr)
    {
        throw std::ios_base::failure(
            "ERROR: Failed to attach to metadata shm segment of size " +
            std::to_string(m_MetadataSize) + " and id " +
            std::to_string(m_MetadataShmID) +
            " from call to ShmSystemV constructor\n");
    }
}

} // end namespace adios