tests/vm/perf_helpers.c

   1 #include <assert.h>
   2 #include <errno.h>
   3 #include <stdarg.h>
   4 #include <stdio.h>
   5 #include <stdlib.h>
   6 #include <string.h>
   7
   8 #include <sys/mman.h>
   9
  10 #include "vm/perf_helpers.h"
  11
  12 #define K_CTIME_BUFFER_LEN  26
  13 void
  14 benchmark_log(bool verbose, const char *restrict fmt, ...)
  15 {
  16         time_t now;
  17         char time_buffer[K_CTIME_BUFFER_LEN];
  18         struct tm local_time;
  19         va_list args;
  20         if (verbose) {
  21                 strncpy(time_buffer, "UNKNOWN", K_CTIME_BUFFER_LEN);
  22
  23                 now = time(NULL);
  24                 if (now != -1) {
  25                         struct tm* ret = localtime_r(&now, &local_time);
  26                         if (ret == &local_time) {
  27                                 snprintf(time_buffer, K_CTIME_BUFFER_LEN,
  28                                     "%.2d/%.2d/%.2d %.2d:%.2d:%.2d",
  29                                     local_time.tm_mon + 1, local_time.tm_mday,
  30                                     local_time.tm_year + 1900,
  31                                     local_time.tm_hour, local_time.tm_min,
  32                                     local_time.tm_sec);
  33                         }
  34                 }
  35
  36                 printf("%s: ", time_buffer);
  37                 va_start(args, fmt);
  38                 vprintf(fmt, args);
  39                 fflush(stdout);
  40         }
  41 }
  42
  43 uint64_t
  44 timespec_difference_us(const struct timespec* a, const struct timespec* b)
  45 {
  46         assert(a->tv_sec >= b->tv_sec || a->tv_nsec >= b->tv_nsec);
  47         long seconds_elapsed = a->tv_sec - b->tv_sec;
  48         uint64_t nsec_elapsed;
  49         if (b->tv_nsec > a->tv_nsec) {
  50                 seconds_elapsed--;
  51                 nsec_elapsed = kNumNanosecondsInSecond - (uint64_t) (b->tv_nsec - a->tv_nsec);
  52         } else {
  53                 nsec_elapsed = (uint64_t) (a->tv_nsec - b->tv_nsec);
  54         }
  55         return (uint64_t) seconds_elapsed * kNumMicrosecondsInSecond + nsec_elapsed / kNumNanosecondsInMicrosecond;
  56 }
  57
  58 unsigned char *
  59 mmap_buffer(size_t memsize)
  60 {
  61         int fd = -1;
  62         unsigned char* addr = (unsigned char *)mmap(NULL, memsize, PROT_READ | PROT_WRITE, MAP_ANON | MAP_PRIVATE,
  63             fd, 0);
  64         if ((void*) addr == MAP_FAILED) {
  65                 fprintf(stderr, "Unable to mmap a memory object: %s\n", strerror(errno));
  66                 exit(2);
  67         }
  68         return addr;
  69 }