serval-dna/nacl/nacl-20110221/cpucycles/monotonic.c
Daniel O'Connor bf9710fd5a Unpacked nacl-20110221 after processing by nacl-prepare-sources.
This only affects build_android, if nacl-gcc-prep is run then build/`uname -s` will be created.
2012-02-27 12:40:14 +10:30

35 lines
692 B
C

#include <time.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/sysctl.h>
static double cpufrequency = 0;
static void init(void)
{
long result = 0; size_t resultlen = sizeof(long);
sysctlbyname("machdep.tsc_freq",&result,&resultlen,0,0);
cpufrequency = result;
}
long long cpucycles_monotonic(void)
{
double result;
struct timespec t;
if (!cpufrequency) init();
clock_gettime(CLOCK_MONOTONIC,&t);
result = t.tv_nsec;
result *= 0.000000001;
result += (double) t.tv_sec;
result *= cpufrequency;
return result;
}
long long cpucycles_monotonic_persecond(void)
{
if (!cpufrequency) init();
return cpufrequency;
}