Identify Heap Contention Errors

// Build:
// gcc main.c -pthread -static -o App10
#include <stdio.h>
#include <pthread.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#define ARR_SIZE 10000
char *pAllocBuf[ARR_SIZE] = {0};
void proc()
{
    while (1)
    {
        int idx = rand() % ARR_SIZE;
        int malloc_size = rand() % ARR_SIZE;
        if (pAllocBuf[idx])
        {
            free(pAllocBuf[idx]);
            pAllocBuf[idx] = 0;
        }
        pAllocBuf[idx] = malloc(malloc_size);
    }
}
#define THREAD_DECLARE(num, func) \
    void bar_##num()               \
    {                              \
        func;                      \
    }                              \
                                   \
    void foo_##num()               \
    {                              \
        bar_##num();               \
    }                              \
                                   \
    void *thread_##num(void *arg) \
    {                              \
        foo_##num();               \
        return 0;                  \
    }
THREAD_DECLARE(one, proc())
THREAD_DECLARE(two, proc())
THREAD_DECLARE(three, proc())
THREAD_DECLARE(four, proc())
THREAD_DECLARE(five, proc())
#define THREAD_CREATE(num)                            \
    {                                                 \
        pthread_t threadID_##num;                     \
        pthread_create(&threadID_##num, NULL, thread_##num, NULL); \
    }
int main(int argc, const char *argv[])
{
    THREAD_CREATE(one)
    THREAD_CREATE(two)
    THREAD_CREATE(three)
    THREAD_CREATE(four)
    THREAD_CREATE(five)
    sleep(-1);
    return 0;
}