buddy/test3.c

   1 /*
   2  * Compile with:
   3  * gcc test3.c mpool.c mstat.c -o test3 -Wall -W -Wextra -ansi -pedantic
   4  */
   5
   6 #include <stdio.h>
   7 #include <stdlib.h>
   8 #include <string.h>  /* for memset() */
   9 #include <time.h>    /* for time() in srand() */
  10
  11 #include "mpool.h"
  12 #include "mstat.h"
  13
  14 #define MAX_BLOCKS 1000
  15
  16 int main(void)
  17 {
  18     char *pblk[MAX_BLOCKS];
  19     mpool_t *mpool;
  20     mpret_t mpret;
  21     size_t an, un;    /* nodes */
  22     size_t ab, ub;    /* blocks */
  23     size_t me, sp;    /* merges, splits */
  24     size_t i, s;
  25
  26     /* Initialize memory pool with 1048576 bytes */
  27     mpret = mpool_init(&mpool, 20, 5);
  28     if (mpret == MPOOL_ENOMEM) {
  29         fprintf(stderr, "mpool: not enough memory\n");
  30         exit(EXIT_FAILURE);
  31     }
  32     else if (mpret == MPOOL_EBADVAL) {
  33         fprintf(stderr, "mpool: bad value passed to mpool_init()\n");
  34         exit(EXIT_FAILURE);
  35     }
  36
  37     /* Initialize random number generator */
  38     srand(time(NULL));
  39
  40     /* Allocate blocks */
  41     for (i = 0; i < MAX_BLOCKS; i++) {
  42         if ((pblk[i] = mpool_alloc(mpool, s = 1 << (5 + rand() % 7))) == NULL)
  43             break;
  44
  45         /*
  46          * Zero out the allocated block
  47          *
  48          * By doing this, there is a chance that we catch
  49          * allocator's bugs, i.e. by writing over the block
  50          * and corrupting next block's header.
  51          */
  52         memset(pblk[i], 0, s);
  53
  54         /* Every now and then free a block to create holes and invoke merges */
  55         if (rand() % 3 == 0) {
  56             mpool_free(mpool, pblk[i]);
  57             pblk[i] = NULL;
  58         }
  59     }
  60
  61     /* Free the rest of the blocks */
  62     for (i = 0; i < MAX_BLOCKS; i++)
  63         if (pblk[i] != NULL)
  64             mpool_free(mpool, pblk[i]);
  65
  66     /* Dump statistics */
  67     mpool_stat_get_nodes(mpool, &an, &un);
  68     mpool_stat_get_bytes(mpool, &ab, &ub);
  69     me = mpool_stat_get_merges(mpool);
  70     sp = mpool_stat_get_splits(mpool);
  71
  72     printf("avail nodes = %-5u\tused nodes = %-5u\tfree(%%) = %.2f\n",
  73            an, un, 100.0 * an / (an + un));
  74     printf("avail bytes = %-5u\tused bytes = %-5u\tfree(%%) = %.2f\n",
  75            ab, ub, 100.0 * ab / (ab + ub));
  76     printf("splits      = %-5u\tmerges     = %-5u\n",
  77            sp, me);
  78
  79     /* Destroy memory pool and free all resources */
  80     mpool_destroy(mpool);
  81
  82     return EXIT_SUCCESS;
  83 }