#include <unistd.h>

#include "concurrency.h"

void walltime_start(walltime_t* start)
{
	clock_gettime(CLOCK_MONOTONIC, start);
}

double walltime_elapsed(const walltime_t* start)
{
	walltime_t finish;
	clock_gettime(CLOCK_MONOTONIC, &finish);

	double elapsed = (finish.tv_sec - start->tv_sec);
	elapsed += (finish.tv_nsec - start->tv_nsec) / 1000000000.0;

	return elapsed;
}

int concurrency_cpu_count()
{
	return sysconf(_SC_NPROCESSORS_ONLN);
}