Source/cmAffinity.cxx

/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
   file Copyright.txt or https://cmake.org/licensing for details.  */
#include "cmAffinity.h"

#include "cm_uv.h"

#ifndef CMAKE_USE_SYSTEM_LIBUV
#ifdef _WIN32
#define CM_HAVE_CPU_AFFINITY
#include <windows.h>
#elif defined(__linux__) || defined(__FreeBSD__)
#define CM_HAVE_CPU_AFFINITY
#include <pthread.h>
#include <sched.h>
#if defined(__FreeBSD__)
#include <pthread_np.h>
#include <sys/cpuset.h>
#include <sys/param.h>
#endif
#if defined(__linux__)
typedef cpu_set_t cm_cpuset_t;
#else
typedef cpuset_t cm_cpuset_t;
#endif
#endif
#endif

namespace cmAffinity {

std::set<size_t> GetProcessorsAvailable()
{
  std::set<size_t> processorsAvailable;
#ifdef CM_HAVE_CPU_AFFINITY
  int cpumask_size = uv_cpumask_size();
  if (cpumask_size > 0) {
#ifdef _WIN32
    DWORD_PTR procmask;
    DWORD_PTR sysmask;
    if (GetProcessAffinityMask(GetCurrentProcess(), &procmask, &sysmask) !=
        0) {
      for (int i = 0; i < cpumask_size; ++i) {
        if (procmask & (((DWORD_PTR)1) << i)) {
          processorsAvailable.insert(i);
        }
      }
    }
#else
    cm_cpuset_t cpuset;
    CPU_ZERO(&cpuset); // NOLINT(clang-tidy)
    if (pthread_getaffinity_np(pthread_self(), sizeof(cpuset), &cpuset) == 0) {
      for (int i = 0; i < cpumask_size; ++i) {
        if (CPU_ISSET(i, &cpuset)) {
          processorsAvailable.insert(i);
        }
      }
    }
#endif
  }
#endif
  return processorsAvailable;
}
}