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glibc  2.9
getloadavg.c
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00001 /* Get system load averages.  Mach version.
00002    Copyright (C) 1999, 2000 Free Software Foundation, Inc.
00003    This file is part of the GNU C Library.
00004 
00005    The GNU C Library is free software; you can redistribute it and/or
00006    modify it under the terms of the GNU Lesser General Public
00007    License as published by the Free Software Foundation; either
00008    version 2.1 of the License, or (at your option) any later version.
00009 
00010    The GNU C Library is distributed in the hope that it will be useful,
00011    but WITHOUT ANY WARRANTY; without even the implied warranty of
00012    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00013    Lesser General Public License for more details.
00014 
00015    You should have received a copy of the GNU Lesser General Public
00016    License along with the GNU C Library; if not, write to the Free
00017    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
00018    02111-1307 USA.  */
00019 
00020 #include <mach.h>
00021 #include <mach/host_info.h>
00022 #include <hurd.h>
00023 #include <errno.h>
00024 #include <unistd.h>
00025 #include <stdlib.h>
00026 
00027 
00028 /* Put the 1 minute, 5 minute and 15 minute load averages
00029    into the first NELEM elements of LOADAVG.
00030    Return the number written (never more than 3, but may be less than NELEM),
00031    or -1 if an error occurred.  */
00032 
00033 int
00034 getloadavg (double loadavg[], int nelem)
00035 {
00036   host_load_info_data_t info;
00037   mach_msg_type_number_t size = HOST_LOAD_INFO_COUNT;
00038   error_t err;
00039   int i;
00040 
00041   err = __host_info (__mach_host_self (), HOST_LOAD_INFO,
00042                    (host_info_t) &info, &size);
00043   if (err)
00044     return __hurd_fail (err);
00045   if (size < HOST_LOAD_INFO_COUNT)
00046     return __hurd_fail (EGRATUITOUS);
00047 
00048   if (nelem > 3)
00049     nelem = 3;
00050   for (i = 0; i < nelem; ++i)
00051     loadavg[i] = (double) info.avenrun[i] / (double) LOAD_SCALE;
00052 
00053   return i;
00054 }