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/*! \internal \file
 * \brief
 * Implements test environment class which performs hardware enumeration for unit tests.
 *
 * \author Aleksei Iupinov <a.yupinov@gmail.com>
 * \author Artem Zhmurov <zhmurov@gmail.com>
 *
 * \ingroup module_testutils
 */

#include "gmxpre.h"

#include "test_hardware_environment.h"

#include <memory>

#include "gromacs/gpu_utils/gpu_utils.h"
#include "gromacs/hardware/detecthardware.h"
#include "gromacs/hardware/device_management.h"
#include "gromacs/hardware/hw_info.h"
#include "gromacs/utility/basenetwork.h"
#include "gromacs/utility/exceptions.h"
#include "gromacs/utility/physicalnodecommunicator.h"

namespace gmx
{
namespace test
{

/* Implements the "construct on first use" idiom to avoid any static
 * initialization order fiasco.
 *
 * Note that thread-safety of the initialization is guaranteed by the
 * C++11 language standard.
 *
 * The pointer itself (not the memory it points to) has no destructor,
 * so there is no deinitialization issue.  See
 * https://isocpp.org/wiki/faq/ctors for discussion of alternatives
 * and trade-offs. */
const TestHardwareEnvironment* getTestHardwareEnvironment()
{
    static TestHardwareEnvironment* testHardwareEnvironment = nullptr;
    if (testHardwareEnvironment == nullptr)
    {
        // Ownership of the TestEnvironment is taken by GoogleTest, so nothing can leak
        testHardwareEnvironment = static_cast<TestHardwareEnvironment*>(
                ::testing::AddGlobalTestEnvironment(new TestHardwareEnvironment));
    }
    return testHardwareEnvironment;
}

void callAddGlobalTestEnvironment()
{
    getTestHardwareEnvironment();
}

TestHardwareEnvironment::TestHardwareEnvironment() :
    hardwareInfo_(gmx_detect_hardware(PhysicalNodeCommunicator{ MPI_COMM_WORLD, gmx_physicalnode_id_hash() }))
{
}

void TestHardwareEnvironment::SetUp()
{
    testDeviceList_.clear();
    // Constructing contexts for all compatible GPUs - will be empty on non-GPU builds
    for (const DeviceInformation& compatibleDeviceInfo : getCompatibleDevices(hardwareInfo_->deviceInfoList))
    {
        setActiveDevice(compatibleDeviceInfo);
        std::string description = getDeviceInformationString(compatibleDeviceInfo);
        testDeviceList_.emplace_back(std::make_unique<TestDevice>(description.c_str(), compatibleDeviceInfo));
    }
}

void TestHardwareEnvironment::TearDown()
{
    testDeviceList_.clear();
    /* In OneAPI 2021.1-beta9 and beta10, there is a bug that cause a
     * segfault when a sycl::device is destructed too late. So, we
     * explicitly destroy device handles here by resetting
     * hardwareInfo_, which does no harm to anything else. */
    hardwareInfo_.reset(nullptr);
}

} // namespace test
} // namespace gmx
