getloadavg.c 1.4 KB

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  1. /*
  2. * Copyright © 2005-2020 Rich Felker, et al.
  3. *
  4. * Permission is hereby granted, free of charge, to any person obtaining
  5. * a copy of this software and associated documentation files (the
  6. * "Software"), to deal in the Software without restriction, including
  7. * without limitation the rights to use, copy, modify, merge, publish,
  8. * distribute, sublicense, and/or sell copies of the Software, and to
  9. * permit persons to whom the Software is furnished to do so, subject to
  10. * the following conditions:
  11. *
  12. * The above copyright notice and this permission notice shall be
  13. * included in all copies or substantial portions of the Software.
  14. *
  15. * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  16. * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  17. * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
  18. * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
  19. * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
  20. * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
  21. * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  22. *
  23. * Imported from musl C library
  24. */
  25. #ifndef _GNU_SOURCE
  26. #define _GNU_SOURCE
  27. #endif /* _GNU_SOURCE */
  28. #include <stdlib.h>
  29. #include <sys/sysinfo.h>
  30. int getloadavg(double *a, int n)
  31. {
  32. struct sysinfo si;
  33. if (n <= 0) return n ? -1 : 0;
  34. sysinfo(&si);
  35. if (n > 3) n = 3;
  36. for (int i=0; i<n; i++)
  37. a[i] = 1.0/(1<<SI_LOAD_SHIFT) * si.loads[i];
  38. return n;
  39. }