dist/ntp/ElectricFence/tstheap.c

   1 /*      $NetBSD$        */
   2
   3 #include <stdlib.h>
   4 #include <stdio.h>
   5 #include <math.h>
   6 #include <limits.h>
   7 #include "efence.h"
   8
   9 /*
  10  * This is a simple program to exercise the allocator. It allocates and frees
  11  * memory in a pseudo-random fashion. It should run silently, using up time
  12  * and resources on your system until you stop it or until it has gone
  13  * through TEST_DURATION (or the argument) iterations of the loop.
  14  */
  15
  16 extern C_LINKAGE double drand48(void); /* For pre-ANSI C systems */
  17
  18 #define POOL_SIZE       1024
  19 #define LARGEST_BUFFER  30000
  20 #define TEST_DURATION   1000000
  21
  22 void *  pool[POOL_SIZE];
  23
  24 #ifdef  FAKE_DRAND48
  25 /*
  26  * Add -DFAKE_DRAND48 to your compile flags if your system doesn't
  27  * provide drand48().
  28  */
  29
  30 #ifndef ULONG_MAX
  31 #define ULONG_MAX       ~(1L)
  32 #endif
  33
  34 double
  35 drand48(void)
  36 {
  37         return (random() / (double)ULONG_MAX);
  38 }
  39 #endif
  40
  41 int
  42 main(int argc, char * * argv)
  43 {
  44         int     count = 0;
  45         int     duration = TEST_DURATION;
  46
  47         if ( argc >= 2 )
  48                 duration = atoi(argv[1]);
  49
  50         for ( ; count < duration; count++ ) {
  51                 void * *        element = &pool[(int)(drand48() * POOL_SIZE)];
  52                 size_t          size = (size_t)(drand48() * (LARGEST_BUFFER + 1));
  53
  54                 if ( *element ) {
  55                         free( *element );
  56                         *element = 0;
  57                 }
  58                 else if ( size > 0 ) {
  59                         *element = malloc(size);
  60                 }
  61         }
  62         return 0;
  63 }