inet/tst-deadline.c

   1 /* Tests for computing deadlines for timeouts.
   2    Copyright (C) 2017-2020 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <inet/net-internal.h>
  20 #include <limits.h>
  21 #include <stdbool.h>
  22 #include <stdint.h>
  23 #include <support/check.h>
  24
  25 /* Find the maximum value which can be represented in a time_t.  */
  26 static time_t
  27 time_t_max (void)
  28 {
  29   _Static_assert (0 > (time_t) -1, "time_t is signed");
  30   uintmax_t current = 1;
  31   while (true)
  32     {
  33       uintmax_t next = current * 2;
  34       /* This cannot happen because time_t is signed.  */
  35       TEST_VERIFY_EXIT (next > current);
  36       ++next;
  37       if ((time_t) next < 0 || next != (uintmax_t) (time_t) next)
  38         /* Value cannot be represented in time_t.  Return the previous
  39            value. */
  40         return current;
  41       current = next;
  42     }
  43 }
  44
  45 static int
  46 do_test (void)
  47 {
  48   {
  49     struct deadline_current_time current_time = __deadline_current_time ();
  50     TEST_VERIFY (current_time.current.tv_sec >= 0);
  51     current_time = __deadline_current_time ();
  52     /* Due to CLOCK_MONOTONIC, either seconds or nanoseconds are
  53        greater than zero.  This is also true for the gettimeofday
  54        fallback.  */
  55     TEST_VERIFY (current_time.current.tv_sec >= 0);
  56     TEST_VERIFY (current_time.current.tv_sec > 0
  57                  || current_time.current.tv_nsec > 0);
  58   }
  59
  60   /* Check basic computations of deadlines.  */
  61   struct deadline_current_time current_time = { { 1, 123456789 } };
  62   struct deadline deadline = __deadline_from_timeval
  63     (current_time, (struct timeval) { 0, 1 });
  64   TEST_VERIFY (deadline.absolute.tv_sec == 1);
  65   TEST_VERIFY (deadline.absolute.tv_nsec == 123457789);
  66   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1);
  67
  68   deadline = __deadline_from_timeval
  69     (current_time, ((struct timeval) { 0, 2 }));
  70   TEST_VERIFY (deadline.absolute.tv_sec == 1);
  71   TEST_VERIFY (deadline.absolute.tv_nsec == 123458789);
  72   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1);
  73
  74   deadline = __deadline_from_timeval
  75     (current_time, ((struct timeval) { 1, 0 }));
  76   TEST_VERIFY (deadline.absolute.tv_sec == 2);
  77   TEST_VERIFY (deadline.absolute.tv_nsec == 123456789);
  78   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1000);
  79
  80   /* Check if timeouts are correctly rounded up to the next
  81      millisecond.  */
  82   for (int i = 0; i < 999999; ++i)
  83     {
  84       ++current_time.current.tv_nsec;
  85       TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1000);
  86     }
  87
  88   /* A full millisecond has elapsed, so the time to the deadline is
  89      now less than 1000.  */
  90   ++current_time.current.tv_nsec;
  91   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 999);
  92
  93   /* Check __deadline_to_ms carry-over.  */
  94   current_time = (struct deadline_current_time) { { 9, 123456789 } };
  95   deadline = (struct deadline) { { 10, 122456789 } };
  96   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 999);
  97   deadline = (struct deadline) { { 10, 122456790 } };
  98   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1000);
  99   deadline = (struct deadline) { { 10, 123456788 } };
 100   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1000);
 101   deadline = (struct deadline) { { 10, 123456789 } };
 102   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 1000);
 103
 104   /* Check __deadline_to_ms overflow.  */
 105   deadline = (struct deadline) { { INT_MAX - 1, 1 } };
 106   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == INT_MAX);
 107
 108   /* Check __deadline_to_ms for elapsed deadlines.  */
 109   current_time = (struct deadline_current_time) { { 9, 123456789 } };
 110   deadline.absolute = current_time.current;
 111   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 0);
 112   current_time = (struct deadline_current_time) { { 9, 123456790 } };
 113   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 0);
 114   current_time = (struct deadline_current_time) { { 10, 0 } };
 115   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 0);
 116   current_time = (struct deadline_current_time) { { 10, 123456788 } };
 117   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 0);
 118   current_time = (struct deadline_current_time) { { 10, 123456789 } };
 119   TEST_VERIFY (__deadline_to_ms (current_time, deadline) == 0);
 120
 121   /* Check carry-over in __deadline_from_timeval.  */
 122   current_time = (struct deadline_current_time) { { 9, 998000001 } };
 123   for (int i = 0; i < 2000; ++i)
 124     {
 125       deadline = __deadline_from_timeval
 126         (current_time, (struct timeval) { 1, i });
 127       TEST_VERIFY (deadline.absolute.tv_sec == 10);
 128       TEST_VERIFY (deadline.absolute.tv_nsec == 998000001 + i * 1000);
 129     }
 130   for (int i = 2000; i < 3000; ++i)
 131     {
 132       deadline = __deadline_from_timeval
 133         (current_time, (struct timeval) { 2, i });
 134       TEST_VERIFY (deadline.absolute.tv_sec == 12);
 135       TEST_VERIFY (deadline.absolute.tv_nsec == 1 + (i - 2000) * 1000);
 136     }
 137
 138   /* Check infinite deadlines.  */
 139   deadline = __deadline_from_timeval
 140     ((struct deadline_current_time) { { 0, 1000 * 1000 * 1000 - 1000 } },
 141      (struct timeval) { time_t_max (), 1 });
 142   TEST_VERIFY (__deadline_is_infinite (deadline));
 143   deadline = __deadline_from_timeval
 144     ((struct deadline_current_time) { { 0, 1000 * 1000 * 1000 - 1001 } },
 145      (struct timeval) { time_t_max (), 1 });
 146   TEST_VERIFY (!__deadline_is_infinite (deadline));
 147   deadline = __deadline_from_timeval
 148     ((struct deadline_current_time)
 149        { { time_t_max (), 1000 * 1000 * 1000 - 1000 } },
 150      (struct timeval) { 0, 1 });
 151   TEST_VERIFY (__deadline_is_infinite (deadline));
 152   deadline = __deadline_from_timeval
 153     ((struct deadline_current_time)
 154        { { time_t_max () / 2 + 1, 0 } },
 155      (struct timeval) { time_t_max () / 2 + 1, 0 });
 156   TEST_VERIFY (__deadline_is_infinite (deadline));
 157
 158   /* Check __deadline_first behavior.  */
 159   deadline = __deadline_first
 160     ((struct deadline) { { 1, 2 } },
 161      (struct deadline) { { 1, 3 } });
 162   TEST_VERIFY (deadline.absolute.tv_sec == 1);
 163   TEST_VERIFY (deadline.absolute.tv_nsec == 2);
 164   deadline = __deadline_first
 165     ((struct deadline) { { 1, 3 } },
 166      (struct deadline) { { 1, 2 } });
 167   TEST_VERIFY (deadline.absolute.tv_sec == 1);
 168   TEST_VERIFY (deadline.absolute.tv_nsec == 2);
 169   deadline = __deadline_first
 170     ((struct deadline) { { 1, 2 } },
 171      (struct deadline) { { 2, 1 } });
 172   TEST_VERIFY (deadline.absolute.tv_sec == 1);
 173   TEST_VERIFY (deadline.absolute.tv_nsec == 2);
 174   deadline = __deadline_first
 175     ((struct deadline) { { 1, 2 } },
 176      (struct deadline) { { 2, 4 } });
 177   TEST_VERIFY (deadline.absolute.tv_sec == 1);
 178   TEST_VERIFY (deadline.absolute.tv_nsec == 2);
 179   deadline = __deadline_first
 180     ((struct deadline) { { 2, 4 } },
 181      (struct deadline) { { 1, 2 } });
 182   TEST_VERIFY (deadline.absolute.tv_sec == 1);
 183   TEST_VERIFY (deadline.absolute.tv_nsec == 2);
 184
 185   return 0;
 186 }
 187
 188 #include <support/test-driver.c>