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/*
* Copyright (c) 2008 The Native Client Authors. All rights reserved.
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE file.
*/
#include <stdio.h>
#include <stdlib.h>
#include <sys/time.h>
#include <time.h>
#include <unistd.h>
#include "native_client/src/trusted/service_runtime/include/sys/nacl_syscalls.h"
int main(int ac,
char **av) {
int opt;
int num_rep = 10000000;
int i;
struct timeval time_start;
struct timeval time_end;
struct timeval time_elapsed;
double time_per_call;
while (EOF != (opt = getopt(ac, av, "r:"))) switch (opt) {
case 'r':
num_rep = strtol(optarg, (char **) NULL, 0);
break;
default:
fprintf(stderr, "Usage: null [-r repetition_count]\n");
return 1;
}
gettimeofday(&time_start, (void *) NULL);
for (i = num_rep; --i >= 0; ) {
null_syscall();
}
gettimeofday(&time_end, (void *) NULL);
time_elapsed.tv_sec = time_end.tv_sec - time_start.tv_sec;
time_elapsed.tv_usec = time_end.tv_usec - time_start.tv_usec;
if (time_elapsed.tv_usec < 0) {
--time_elapsed.tv_sec;
time_elapsed.tv_usec += 1000000;
}
printf("Number of null syscalls: %d\n", num_rep);
printf("Elapsed time: %d.%06dS\n",
(int) time_elapsed.tv_sec,
(int) time_elapsed.tv_usec);
time_per_call = ((time_elapsed.tv_sec + time_elapsed.tv_usec / 1.0e6)
/ num_rep);
printf("Time per call: %gS or %fnS\n",
time_per_call,
1.0e9 * time_per_call);
printf("Calls per sec: %d\n", (int) (1.0 / time_per_call));
return 0;
}
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