Processor affinity: convenience functions for binding threads to cores (nonstandard)

affinity.h

#ifndef _GNU_SOURCE
#define _GNU_SOURCE
#endif

#include <pthread.h>
#include <sched.h>

#include "overload_set_thread_affinity.h"

static inline void set_thread_affinity(pthread_t t, int cpu)
{
    cpu_set_t cpuset;

    CPU_ZERO(&cpuset);
    CPU_SET(cpu, &cpuset);
    pthread_setaffinity_np(t, sizeof(cpu_set_t), &cpuset);
}

static inline void set_thread_affinity(int cpu)
{
    return set_thread_affinity(pthread_self(), cpu);
}

static inline int get_thread_affinity(void)
{
    cpu_set_t cpuset;
    int i;

    pthread_getaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset);

    for (i = 0; i < CPU_SETSIZE; i++) {
        if (CPU_ISSET(i, &cpuset))
            break;
    }

    return i;
}

static inline int cpu_count(void)
{
    cpu_set_t cpuset;
	
    // Requires unrestricted affinity! 
    pthread_getaffinity_np(pthread_self(), sizeof(cpu_set_t), &cpuset);

    return CPU_COUNT(&cpuset);
}