1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
|
// example based on https://en.cppreference.com/w/cpp/memory/shared_ptr
#if defined __GNUC__ || defined __linux__
#include <stdio.h>
#include <unistd.h>
#include <pthread.h>
#include <time.h>
struct Base
{
int value;
} typedef Base;
#define i_val Base
#define i_drop(x) printf("Base::~Base()\n")
#define i_tag base
#define i_opt c_no_cmp
#include <stc/csptr.h>
void* thr(csptr_base* lp)
{
sleep(1);
static pthread_mutex_t mtx = PTHREAD_MUTEX_INITIALIZER;
c_autoscope (pthread_mutex_lock(&mtx), pthread_mutex_unlock(&mtx))
{
printf("local pointer in a thread:\n"
" p.get() = %p, p.use_count() = %ld\n", (void*)lp->get, *lp->use_count);
}
/* atomically decrease ref. */
csptr_base_drop(lp);
return NULL;
}
int main()
{
csptr_base p = csptr_base_from((Base){42});
printf("Created a Base\n"
" p.get() = %p, p.use_count() = %ld\n", (void*)p.get, *p.use_count);
enum {N = 3};
pthread_t t[N];
csptr_base c[N];
c_forrange (i, N) {
c[i] = csptr_base_clone(p);
pthread_create(&t[i], NULL, (void*(*)(void*))thr, &c[i]);
}
printf("Shared ownership between %d threads and released\n"
"ownership from main:\n"
" p.get() = %p, p.use_count() = %ld\n", N, (void*)p.get, *p.use_count);
csptr_base_reset(&p);
c_forrange (i, N) pthread_join(t[i], NULL);
printf("All threads completed, the last one deleted Base\n");
}
#else
int main() {}
#endif
|
