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#include <pthread.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define NUM_THREADS 10
#define ALLOCATIONS 1024 * 100
#define SIZE 1024
static void do_work()
{
void** ptrs;
ptrs = malloc(sizeof(void*) * ALLOCATIONS);
if (ptrs == NULL) {
perror("malloc");
return;
}
for(int i = 0; i < ALLOCATIONS; i++)
{
ptrs[i] = malloc(SIZE);
memset(ptrs[i], 0, SIZE);
}
for(int i = 0; i < ALLOCATIONS; i++)
{
free(malloc(SIZE));
}
for(int i = 0; i < ALLOCATIONS; i++)
{
/* memset(ptrs[i], 0, SIZE); */
free(ptrs[i]);
}
for(int i = 0; i < ALLOCATIONS; i++)
{
free(malloc(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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