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#include <stdio.h>
#include <stdlib.h>
#include <assert.h>
#include "../memcheck.h"
/*
Incompetent memory management
Simulate what happens when trying to manage a dense brancy cyclic
structure with refcounting.
*/
static int bytes, blocks;
struct node {
struct node *l, *r;
int ref;
};
static void ref(struct node *n)
{
if (n)
n->ref++;
}
static void unref(struct node *n)
{
if (n && --n->ref == 0) {
bytes -= sizeof(*n);
blocks--;
free(n);
}
}
static struct node *alloc()
{
struct node *n = malloc(sizeof(*n));
n->l = n->r = NULL;
n->ref = 0;
bytes += sizeof(*n);
blocks++;
return n;
}
static void assign(struct node **np, struct node *n)
{
ref(n);
unref(*np);
*np = n;
}
static int rrange(int range)
{
long long ret = rand() * (long long)range;
return (int)(ret / RAND_MAX);
}
#define ITER 100000
#define N 1000
static struct node *nodes[N];
static struct node *mk()
{
int idx = rrange(N);
struct node *n;
/*
50% recycle
25% alloc new
25% return NULL
*/
if (rand() > RAND_MAX/2) {
/* recycle existing block */
n = nodes[idx];
} else if (rand() > RAND_MAX/2) {
/* alloc new block */
n = alloc();
assign(&n->l, mk());
assign(&n->r, mk());
} else {
/* no block */
n = NULL;
}
assign(&nodes[idx], n);
return n;
}
int main()
{
int i;
long base_definite, base_dubious, base_reachable, base_suppressed;
long definite, dubious, reachable, suppressed;
int total;
/* we require these longs to have same size as a machine word */
assert(sizeof(long) == sizeof(void*));
/* get a baseline in case the runtime allocated some memory */
VALGRIND_DO_LEAK_CHECK;
base_definite = base_dubious = base_reachable = base_suppressed = 0;
VALGRIND_COUNT_LEAKS(base_definite, base_dubious,
base_reachable, base_suppressed);
for(i = 0; i < ITER; i++) {
mk();
if ((i % (ITER/10)) == 0) {
if (0)
printf("%d living blocks, %d bytes\n",
blocks, bytes);
VALGRIND_DO_LEAK_CHECK;
}
}
/* "free all memory" */
for(i = 0; i < N; i++)
assign(&nodes[i], NULL);
if (0)
printf("FINISHED: %d living blocks, %d bytes\n",
blocks, bytes);
VALGRIND_DO_LEAK_CHECK;
/* Shouldn't be necessary, but COUNT_LEAKS doesn't define its
result values */
definite = dubious = reachable = suppressed = 0;
VALGRIND_COUNT_LEAKS(definite, dubious, reachable, suppressed);
definite -= base_definite;
dubious -= base_dubious;
reachable -= base_reachable;
suppressed -= base_suppressed;
total = definite+dubious+reachable+suppressed;
if (0)
printf("leaks: definite %d, dubious %d, reachable %d, suppressed %d = %d\n",
(int)definite, (int)dubious, (int)reachable, (int)suppressed, total);
if (reachable != 0)
printf("FAILED: I freed everything, "
"but there's still %d bytes reachable\n",
(int)reachable);
else if (total != bytes)
printf("FAILED: I count %d bytes, leakcheck says %d\n",
bytes, total);
else
printf("PASS\n");
return 0;
}
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