1 #include "threads_impl.h"
2
3 // C11 does not define any way for applications to know the maximum
4 // number of tss_t slots. pthreads, however, does, via the
5 // PTHREAD_KEYS_MAX constant. So we allow that bit of pthreads to
6 // bleed over here (and into sysconf, which also reports the value)
7 // rather than go through some circuituous pattern to define an
8 // internal constant that's just the same as the pthread one.
9
10 typedef void (*key_t)(void*);
_Atomic(key_t)11 static _Atomic(key_t) keys[PTHREAD_KEYS_MAX];
12
13 static void nodtor(void* dummy) {}
14
tss_create(tss_t * k,void (* dtor)(void *))15 int tss_create(tss_t* k, void (*dtor)(void*)) {
16 unsigned i = (uintptr_t)&k / 16 % PTHREAD_KEYS_MAX;
17 unsigned j = i;
18
19 if (!dtor)
20 dtor = nodtor;
21 do {
22 key_t expected = NULL;
23 if (atomic_compare_exchange_strong(&keys[j], &expected, dtor)) {
24 *k = j;
25 return 0;
26 }
27 } while ((j = (j + 1) % PTHREAD_KEYS_MAX) != i);
28 return EAGAIN;
29 }
30
tss_delete(tss_t k)31 void tss_delete(tss_t k) {
32 atomic_store(&keys[k], NULL);
33 }
34
__thread_tsd_run_dtors(void)35 void __thread_tsd_run_dtors(void) {
36 thrd_t self = __thrd_current();
37 int i, j, not_finished = self->tsd_used;
38 for (j = 0; not_finished && j < TSS_DTOR_ITERATIONS; j++) {
39 not_finished = 0;
40 for (i = 0; i < PTHREAD_KEYS_MAX; i++) {
41 if (self->tsd[i] && atomic_load(&keys[i])) {
42 void* tmp = self->tsd[i];
43 self->tsd[i] = 0;
44 atomic_load(&keys[i])(tmp);
45 not_finished = 1;
46 }
47 }
48 }
49 }
50