maxconns.c

   1 /*
   2  * Copyright (C) 2012-2020 all contributors <cmogstored-public@yhbt.net>
   3  * License: GPL-3.0+ <https://www.gnu.org/licenses/gpl-3.0.txt>
   4  */
   5 #include "cmogstored.h"
   6 #include <sys/time.h>
   7 #include <sys/resource.h>
   8
   9 #ifndef RLIM_INFINITY
  10 #  define RLIM_INFINITY ((rlim_t)(-1))
  11 #endif
  12
  13 void mog_set_maxconns(unsigned long maxconns)
  14 {
  15         struct rlimit r;
  16         rlim_t want;
  17         struct rlimit orig;
  18
  19         if (getrlimit(RLIMIT_NOFILE, &r) != 0)
  20                 die_errno("getrlimit(RLIMIT_NOFILE) failed");
  21
  22         memcpy(&orig, &r, sizeof(struct rlimit));
  23
  24         if (maxconns == 0)
  25                 maxconns = MOG_DEFAULT_MAXCONNS;
  26         want = maxconns;
  27
  28         if ((int)want < 0 || want > MOG_FD_MAX)
  29                 want = MOG_FD_MAX; /* LOL :D */
  30         if (r.rlim_cur >= want)
  31                 return;
  32
  33         if (r.rlim_max == RLIM_INFINITY || r.rlim_cur == RLIM_INFINITY) {
  34                 /* insane? maybe... */
  35                 r.rlim_max = r.rlim_cur = want;
  36         } else if (r.rlim_max == 0) {
  37                 warn("RLIMIT_NOFILE max=0, trying %ld anyways", (long)want);
  38                 r.rlim_max = r.rlim_cur = want;
  39         } else if (r.rlim_max < want) {
  40                 warn("RLIMIT_NOFILE max=%ld less than wanted value=%ld",
  41                      (long)r.rlim_max, (long)want);
  42                 r.rlim_cur = r.rlim_max;
  43         } else {
  44                 r.rlim_max = r.rlim_cur = want;
  45         }
  46
  47         if (setrlimit(RLIMIT_NOFILE, &r) == 0) return;
  48
  49         warn("failed to set RLIMIT_NOFILE max=%ld cur=%ld (maxconns=%lu)",
  50              (long)r.rlim_max, (long)r.rlim_cur, maxconns);
  51
  52         while ((want -= 64) >= maxconns) {
  53                 r.rlim_max = r.rlim_cur = want;
  54                 if (setrlimit(RLIMIT_NOFILE, &r) == 0)
  55                         goto eventual_success;
  56         }
  57
  58         warn("RLIMIT_NOFILE stuck at  max=%ld cur=%ld (maxconns=%lu)",
  59              (long)orig.rlim_max, (long)orig.rlim_cur, maxconns);
  60         return;
  61
  62 eventual_success:
  63         warn("set RLIMIT_NOFILE max=%ld cur=%ld (maxconns=%lu)",
  64              (long)r.rlim_max, (long)r.rlim_cur, maxconns);
  65 }