timer.c

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/**
 * @file timer.c
 * @brief Provides functions for collecting run-time statistics such as CPU time, memory usage, I/O counts, and elapsed time.
 *
 * @details
 * This file contains implementations of functions like `init_stats()`, `cpu_time()`, `memory_count()`, and others,
 * which collect various run-time statistics. The implementations vary depending on the operating system
 * (VAX/VMS, SUN UNIX, Linux, Solaris, etc.). The functions utilize system-specific libraries and system calls
 * to retrieve the necessary information.
 *
 * @copyright 
 *   - (c) 2002 The University of Chicago, as Operator of Argonne National Laboratory.
 *   - (c) 2002 The Regents of the University of California, as Operator of Los Alamos National Laboratory.
 *
 * @license 
 * This file is distributed under the terms of the Software License Agreement
 * found in the file LICENSE included with this distribution.
 *
 * @author M. Borland, C Saunders, R. Soliday, Y. Wang
 */
 
#include "mdb.h"
 
double delapsed_time(void);
 
/* routine elapsed_time() returns the clock time elapsed since init_stats()
 * was last called, as a character string
 */
 
char *elapsed_time() {
  static MDB_THREAD_LOCAL char buffer[20];
  double dtime;
  int h, m;
  float s;
 
  dtime = delapsed_time();
  h = dtime / 3600;
  dtime -= h * 3600;
  m = dtime / 60;
  dtime -= m * 60;
  s = dtime;
 
  sprintf(buffer, "%02d:%02d:%02.3f", h, m, s);
  return (buffer);
}
 
# if defined(_WIN32)
#  include <time.h>
# else
#  if defined(vxWorks)
#   include <sysLib.h>
#   include <time.h>
#  else
#   if defined(linux)
#    include <time.h>
#   endif
#   if defined(__rtems__)
#    include <unistd.h>
#   endif
#   include <sys/time.h>
#  endif
# endif
 
# if defined(linux)
static MDB_THREAD_LOCAL struct timespec delapsedStart;
static MDB_THREAD_LOCAL short delapsedStartInitialized = 0;
/**
 * @brief Initializes the run-time statistics collection.
 *
 * This function initializes the timer by calling system-specific initialization routines.
 * It should be called before collecting any run-time statistics.
 */
void init_stats() {
  clock_gettime(CLOCK_REALTIME, &delapsedStart);
  delapsedStartInitialized = 1;
}
# else
static MDB_THREAD_LOCAL double delapsed_start = 0;
void init_stats() {
  delapsed_start = delapsed_time();
  clock();
}
# endif
 
/**
 * @brief Calculates the elapsed clock time since the last initialization as a numerical value.
 *
 * This function calculates the elapsed time in seconds since `init_stats()` was last called.
 *
 * @return The elapsed time in seconds, or 0.0 if not available.
 */
double delapsed_time() {
# if defined(linux)
  struct timespec delapsedNow;
  if (!delapsedStartInitialized)
    init_stats();
  clock_gettime(CLOCK_REALTIME, &delapsedNow);
  return (double)(delapsedNow.tv_sec - delapsedStart.tv_sec) +
    (delapsedNow.tv_nsec - delapsedStart.tv_nsec)/1e9;
# else
  static MDB_THREAD_LOCAL long delapsed_start = -1;
  if (delapsed_start == -1) {
    delapsed_start = time(0);
    return 0.0;
  } else
    return time(0) - delapsed_start;
# endif
}
 
/**
 * @brief Retrieves the CPU time used since the last initialization.
 *
 * This function retrieves the CPU time consumed by the process since `init_stats()` was last called.
 *
 * @return The CPU time used in hundredths of seconds, or -1 on error.
 */
long cpu_time() {
  return (long)((clock() * 100.0) / CLOCKS_PER_SEC);
}
 
/* routine bio_count() returns the buffered io count since init_stats() was
 * last called
 */
 
long bio_count() {
  return 0;
}
 
/* routine dio_count() returns the direct io count since init_stats() was
 * last called
 */
 
long dio_count() {
  return (0);
}
 
/**
 * @brief Retrieves the number of page faults since the last initialization.
 *
 * This function retrieves the number of page faults that have occurred since `init_stats()` was last called.
 *
 * @return The number of page faults, or -1 on error.
 */
long page_faults() {
  return 0;
}
 
# if defined(linux) && !defined(__powerpc__)
#  include <stdio.h>
#  include <sys/types.h>
#  include <unistd.h>
 
/**
 * @brief Retrieves the memory usage count since the last initialization.
 *
 * This function retrieves the memory usage information in kilobytes since `init_stats()` was last called.
 *
 * @return The memory usage in kilobytes, or 0 on error.
 */
long memory_count()
{
  FILE *fp;
  long size, resident, pageSize;
 
  if (!(fp = fopen("/proc/self/statm", "r"))) {
    perror("fopen failed in memory_count()");
    exit(1);
  }
  if (fscanf(fp, "%ld %ld", &size, &resident) != 2) {
    perror("fscanf failed in memory_count()");
    exit(1);
  }
  fclose(fp);
  pageSize = sysconf(_SC_PAGESIZE);
  return resident*(pageSize/1024);
}
# else
long memory_count() {
  return 0;
}
# endif