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[exim.git] / src / OS / os.c-GNU

/*************************************************
*     Exim - an Internet mail transport agent    *
*************************************************/

/* Copyright (c) The Exim Maintainers 2020 */
/* See the file NOTICE for conditions of use and distribution. */

/* GNU-specific code. This is concatenated onto the generic src/os.c file.
GNU/Hurd has approximately the same way to determine the load average as NeXT,
so a variant of this could also be in the generic os.c file. See the GNU EMacs
getloadavg.c file, from which this snippet was derived. getloadavg.c from Emacs
is copyrighted by the FSF under the terms of the GPLv2 or any later version.
Changes are hereby placed under the same license, as requested by the GPL. */

#ifndef OS_LOAD_AVERAGE
#define OS_LOAD_AVERAGE

#include <mach.h>

static processor_set_t default_set;
static int getloadavg_initialized;

int
os_getloadavg (void)
{
host_t host;
struct processor_set_basic_info info;
unsigned info_count;

if (!getloadavg_initialized)
  {
  if (processor_set_default (mach_host_self(), &default_set) == KERN_SUCCESS)
    getloadavg_initialized = 1;
  }

if (getloadavg_initialized)
  {
  info_count = PROCESSOR_SET_BASIC_INFO_COUNT;
  if (processor_set_info(default_set, PROCESSOR_SET_BASIC_INFO, &host,
       (processor_set_info_t)&info, &info_count) != KERN_SUCCESS)
    getloadavg_initialized = 0;
  else
    {
    #if LOAD_SCALE == 1000
    return info.load_average;
    #else
    return (int) (((double) info.load_average * 1000) / LOAD_SCALE));
    #endif
    }
  }

return -1;
}
#endif  /* OS_LOAD_AVERAGE */

/* End of os.c-GNU */