Files
stgsharp/StgSharp.Native/sn-src/t.affinity.c
T

56 lines
2.0 KiB
C

#include "sn_target.h"
#include "StgSharpNative.h"
#if SN_IS_OS(SN_OS_LINUX)
#define _GNU_SOURCE
#include <pthread.h>
#include <sched.h>
#include <unistd.h>
#endif
/* Pin the calling thread to a single logical processor.
* core_id >= 0 : bind to that logical processor (global index, across groups).
* core_id < 0 : clear affinity constraint within the current group. */
SN_API void SN_DECL sn_set_thread_affinity(int core_id)
{
#if SN_IS_OS(SN_OS_WINDOWS)
if (core_id < 0) {
/* Query which group the thread currently belongs to */
GROUP_AFFINITY current;
GetThreadGroupAffinity(GetCurrentThread(), &current);
/* Build a full mask for that group's actual core count */
DWORD count = GetActiveProcessorCount(current.Group);
GROUP_AFFINITY ga;
memset(&ga, 0, sizeof(ga));
ga.Group = current.Group;
ga.Mask = (count >= 64) ? ~(KAFFINITY)0
: ((KAFFINITY)1 << count) - 1;
SetThreadGroupAffinity(GetCurrentThread(), &ga, NULL);
return;
}
WORD group = (WORD)(core_id / 64);
int index = core_id % 64;
DWORD count = GetActiveProcessorCount(group);
if ((DWORD)index >= count)
return;
GROUP_AFFINITY ga;
memset(&ga, 0, sizeof(ga));
ga.Group = group;
ga.Mask = (KAFFINITY)1 << index;
SetThreadGroupAffinity(GetCurrentThread(), &ga, NULL);
#elif SN_IS_OS(SN_OS_LINUX)
cpu_set_t set;
if (core_id < 0) {
CPU_ZERO(&set);
long ncpus = sysconf(_SC_NPROCESSORS_ONLN);
for (long i = 0; i < ncpus; i++)
CPU_SET((int)i, &set);
} else {
CPU_ZERO(&set);
CPU_SET(core_id, &set);
}
pthread_setaffinity_np(pthread_self(), sizeof(set), &set);
#endif
}