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#include <malloc.h>
#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define NUM_THREADS 10
#define LIFE_DATA (1024l * 1024 * 100) // 100 MiB
#define ALLOCATIONS 100000l // 100000
#define MAX_SIZE (1024l * 16) // 16KiB
typedef struct chunk {
struct chunk* next;
char data[];
} chunk_t;
static inline size_t rand_size()
{
return (rand() % MAX_SIZE) + sizeof(chunk_t);
}
static void do_work()
{
chunk_t* head = NULL;
chunk_t* tail = NULL;
size_t to_allocate = LIFE_DATA;
// allocate life data
while(to_allocate > 0) {
size_t size = rand_size();
if (size > to_allocate)
size = to_allocate;
to_allocate -= size;
chunk_t* cur = (chunk_t*) malloc(size);
// touch memory
memset(&cur->data, 0, size - sizeof(struct chunk*));
if(!head) {
head = tail = cur;
}
else {
tail->next = cur;
tail = cur;
}
}
// Do some random allocations to change the allocators state
for(int i = 0; i < ALLOCATIONS; i++)
{
free(malloc(rand_size()));
}
// free life data
do {
chunk_t* next = head->next;
free(head);
head = next;
} while(head != tail);
// Do some random allocations to change the allocators state
for(int i = 0; i < ALLOCATIONS; i++)
{
free(malloc(rand_size()));
}
return;
}
static void* thread_func(void* arg)
{
unsigned int* thread_id = (unsigned int*)arg;
pthread_t next_thread;
printf("thread %d doing work\n", *thread_id);
do_work();
if (*thread_id == NUM_THREADS)
return NULL;
printf("thread %d spawning new thread work\n", *thread_id);
*thread_id = (*thread_id) + 1;
if (0 != pthread_create(&next_thread, NULL, thread_func, arg)) {
perror("pthread_create");
return NULL;
}
printf("thread %d joining thread %d work\n", *thread_id-1, *thread_id);
if (0 != pthread_join(next_thread, NULL)) {
perror("pthread_join");
return NULL;
}
return NULL;
}
int main()
{
unsigned int thread_count = 0;
pthread_t first;
do_work();
if (0 != pthread_create(&first, NULL, thread_func, &thread_count)) {
perror("pthread_create");
return 1;
}
if (0 != pthread_join(first, NULL)) {
perror("pthread_join");
return 1;
}
return 0;
}
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