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_ERANGE) {
  33         fprintf(stderr, "mpool: out of range in mpool_init()\n");
  34         exit(EXIT_FAILURE);
  35     }
  36     else if (mpret == MPOOL_EBADVAL) {
  37         fprintf(stderr, "mpool: bad value passed to mpool_init()\n");
  38         exit(EXIT_FAILURE);
  39     }
  40
  41     /* Initialize random number generator */
  42     srand(time(NULL));
  43
  44     /* Allocate blocks */
  45     for (i = 0; i < MAX_BLOCKS; i++) {
  46         if ((pblk[i] = mpool_alloc(mpool, s = 1 << (5 + rand() % 7))) == NULL)
  47             break;
  48
  49         /*
  50          * Zero out the allocated block
  51          *
  52          * By doing this, there is a chance that we catch
  53          * allocator's bugs, i.e. by writing over the block
  54          * and corrupting next block's header.
  55          */
  56         memset(pblk[i], 0, s);
  57
  58         /* Every now and then free a block to create holes and invoke merges */
  59         if (rand() % 3 == 0) {
  60             mpool_free(mpool, pblk[i]);
  61             pblk[i] = NULL;
  62         }
  63     }
  64
  65     /* Free the rest of the blocks */
  66     for (i = 0; i < MAX_BLOCKS; i++)
  67         if (pblk[i] != NULL)
  68             mpool_free(mpool, pblk[i]);
  69
  70     /* Dump statistics */
  71     mpool_stat_get_nodes(mpool, &an, &un);
  72     mpool_stat_get_bytes(mpool, &ab, &ub);
  73     me = mpool_stat_get_merges(mpool);
  74     sp = mpool_stat_get_splits(mpool);
  75
  76     printf("avail nodes = %-5u\tused nodes = %-5u\tfree(%%) = %.2f\n",
  77            an, un, 100.0 * an / (an + un));
  78     printf("avail bytes = %-5u\tused bytes = %-5u\tfree(%%) = %.2f\n",
  79            ab, ub, 100.0 * ab / (ab + ub));
  80     printf("splits      = %-5u\tmerges     = %-5u\n",
  81            sp, me);
  82
  83     /* Destroy memory pool and free all resources */
  84     mpool_destroy(mpool);
  85
  86     return EXIT_SUCCESS;
  87 }