src/OS/os.c-GNU

   1 /*************************************************
   2 *     Exim - an Internet mail transport agent    *
   3 *************************************************/
   4
   5 /* Copyright (c) The Exim Maintainers 2020 */
   6 /* See the file NOTICE for conditions of use and distribution. */
   7
   8 /* GNU-specific code. This is concatenated onto the generic src/os.c file.
   9 GNU/Hurd has approximately the same way to determine the load average as NeXT,
  10 so a variant of this could also be in the generic os.c file. See the GNU EMacs
  11 getloadavg.c file, from which this snippet was derived. getloadavg.c from Emacs
  12 is copyrighted by the FSF under the terms of the GPLv2 or any later version.
  13 Changes are hereby placed under the same license, as requested by the GPL. */
  14
  15 #ifndef OS_LOAD_AVERAGE
  16 #define OS_LOAD_AVERAGE
  17
  18 #include <mach.h>
  19
  20 static processor_set_t default_set;
  21 static int getloadavg_initialized;
  22
  23 int
  24 os_getloadavg (void)
  25 {
  26 host_t host;
  27 struct processor_set_basic_info info;
  28 unsigned info_count;
  29
  30 if (!getloadavg_initialized)
  31   {
  32   if (processor_set_default (mach_host_self(), &default_set) == KERN_SUCCESS)
  33     getloadavg_initialized = 1;
  34   }
  35
  36 if (getloadavg_initialized)
  37   {
  38   info_count = PROCESSOR_SET_BASIC_INFO_COUNT;
  39   if (processor_set_info(default_set, PROCESSOR_SET_BASIC_INFO, &host,
  40        (processor_set_info_t)&info, &info_count) != KERN_SUCCESS)
  41     getloadavg_initialized = 0;
  42   else
  43     {
  44     #if LOAD_SCALE == 1000
  45     return info.load_average;
  46     #else
  47     return (int) (((double) info.load_average * 1000) / LOAD_SCALE));
  48     #endif
  49     }
  50   }
  51
  52 return -1;
  53 }
  54 #endif  /* OS_LOAD_AVERAGE */
  55
  56 /* End of os.c-GNU */