tests/regression/ust/getcpu-override/lttng-ust-getcpu-override-test.c

   1 /*
   2  * lttng-ust-getcpu-override-test.c
   3  * Based on lttng-getcpu-override-example.c from LTTng-ust exemple
   4  *
   5  * Copyright (c) 2014 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   6  * Copyright (c) 2015 Jonathan Rajotte <jonathan.rajotte-julien@efficios.com>
   7  *
   8  * Permission is hereby granted, free of charge, to any person obtaining a copy
   9  * of this software and associated documentation files (the "Software"), to deal
  10  * in the Software without restriction, including without limitation the rights
  11  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  12  * copies of the Software, and to permit persons to whom the Software is
  13  * furnished to do so, subject to the following conditions:
  14  *
  15  * The above copyright notice and this permission notice shall be included in
  16  * all copies or substantial portions of the Software.
  17  *
  18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  20  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  21  * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  22  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  23  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  24  * SOFTWARE.
  25  */
  26
  27 #include <stdlib.h>
  28 #include <common/compat/time.h>
  29 #include <string.h>
  30 #include <stdio.h>
  31 #include <unistd.h>
  32 #include <lttng/ust-getcpu.h>
  33
  34 static long nprocessors;
  35
  36 int plugin_getcpu(void)
  37 {
  38         /* Generate a sequence based on the number of configurated processor
  39          * by using sequence[i] % nb_configured_processors. Where sequence
  40          * is a static random sequence.
  41          * The expected cpu_id sequence can be regenerated on the test script
  42          * side and compared to the extracted cpu sequence for validation.
  43          * This does no guarantee in absolute the validity of the getcpu
  44          * plugin but provide a strong argument of it's validity.
  45          */
  46         static int i = 0;
  47         static int seq_seed[256] = { 100, 57, 232, 236, 42, 193, 224, 184, 216,
  48                 150, 92, 91, 108, 118, 55, 243, 65, 101, 209, 0, 147, 36, 29,
  49                 34, 49, 188, 174, 105, 253, 245, 227, 238, 112, 20, 222, 201,
  50                 102, 175, 119, 19, 132, 41, 78, 90, 114, 64, 138, 14, 48, 18,
  51                 162, 85, 204, 124, 133, 73, 172, 106, 241, 126, 28, 104, 111,
  52                 21, 127, 219, 9, 244, 237, 189, 59, 214, 52, 141, 107, 26, 25,
  53                 199, 3, 157, 117, 234, 33, 44, 46, 84, 69, 155, 122, 250, 231,
  54                 86, 239, 76, 190, 120, 1, 94, 206, 8, 148, 159, 167, 215, 164,
  55                 31, 217, 61, 71, 125, 68, 109, 195, 177, 95, 82, 142, 182, 129,
  56                 87, 37, 140, 134, 186, 173, 39, 116, 143, 254, 229, 131, 67,
  57                 121, 192, 240, 15, 221, 30, 242, 185, 80, 170, 135, 51, 187,
  58                 194, 246, 12, 225, 181, 137, 211, 228, 88, 218, 27, 233, 161,
  59                 77, 252, 123, 93, 220, 248, 205, 223, 144, 128, 196, 70, 247,
  60                 210, 178, 203, 154, 24, 169, 149, 163, 35, 7, 151, 103, 197,
  61                 139, 165, 158, 207, 72, 113, 145, 45, 183, 11, 198, 43, 81, 230,
  62                 97, 96, 2, 66, 213, 146, 179, 22, 58, 54, 38, 160, 200, 235,
  63                 226, 156, 56, 208, 249, 32, 176, 168, 110, 191, 79, 152, 115,
  64                 10, 74, 60, 251, 17, 83, 180, 171, 202, 40, 166, 255, 53, 212,
  65                 98, 5, 50, 99, 4, 89, 13, 63, 6, 136, 153, 23, 16, 47, 130, 75,
  66                 62 };
  67         int ret;
  68
  69         ret = seq_seed[i] % nprocessors;
  70         i++;
  71         i = i % 256;
  72         return ret;
  73 }
  74
  75 void lttng_ust_getcpu_plugin_init(void)
  76 {
  77         int ret;
  78
  79         nprocessors = sysconf(_SC_NPROCESSORS_CONF);
  80         if (nprocessors < 0) {
  81                 perror("Failed to get _SC_NPROCESSORS_CONF");
  82                 goto error;
  83         }
  84
  85         ret = lttng_ust_getcpu_override(plugin_getcpu);
  86         if (ret) {
  87                 fprintf(stderr, "Error enabling getcpu override: %s\n",
  88                         strerror(-ret));
  89                 goto error;
  90         }
  91         return;
  92
  93 error:
  94         exit(EXIT_FAILURE);
  95 }