LinuxPlatformMisc.cpp

/*
 *  Copyright 2019-2022 Diligent Graphics LLC
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *  In no event and under no legal theory, whether in tort (including negligence),
 *  contract, or otherwise, unless required by applicable law (such as deliberate
 *  and grossly negligent acts) or agreed to in writing, shall any Contributor be
 *  liable for any damages, including any direct, indirect, special, incidental,
 *  or consequential damages of any character arising as a result of this License or
 *  out of the use or inability to use the software (including but not limited to damages
 *  for loss of goodwill, work stoppage, computer failure or malfunction, or any and
 *  all other commercial damages or losses), even if such Contributor has been advised
 *  of the possibility of such damages.
 */

#include "LinuxPlatformMisc.hpp"

#include <pthread.h>

#ifdef PLATFORM_FREEBSD
#    include <pthread_np.h>
#endif

namespace Diligent
{

Uint64 LinuxMisc::SetCurrentThreadAffinity(Uint64 Mask)
{
    const auto CurrThread = pthread_self();

    Uint64 CurrAffinity = 0;

    cpu_set_t CPUSet;
    if (pthread_getaffinity_np(CurrThread, sizeof(CPUSet), &CPUSet) == 0)
    {
        for (Uint32 j = 0; j < 64; ++j)
        {
            if (CPU_ISSET(j, &CPUSet))
                CurrAffinity |= Uint64{1} << j;
        }
    }

    CPU_ZERO(&CPUSet);
    for (Uint32 j = 0; j < 64; j++)
    {
        if (Mask & (Uint64{1} << j))
            CPU_SET(j, &CPUSet);
    }

    if (pthread_setaffinity_np(CurrThread, sizeof(CPUSet), &CPUSet) == 0)
        return CurrAffinity;
    else
        return 0;
}

} // namespace Diligent