fusl/src/thread/pthread_key_create.c

#include "pthread_impl.h"

volatile size_t __pthread_tsd_size = sizeof(void*) * PTHREAD_KEYS_MAX;
void* __pthread_tsd_main[PTHREAD_KEYS_MAX] = {0};

static void (*volatile keys[PTHREAD_KEYS_MAX])(void*);

static void nodtor(void* dummy) {}

int __pthread_key_create(pthread_key_t* k, void (*dtor)(void*)) {
  unsigned i = (uintptr_t)&k / 16 % PTHREAD_KEYS_MAX;
  unsigned j = i;
  pthread_t self = __pthread_self();

  /* This can only happen in the main thread before
   * pthread_create has been called. */
  if (!self->tsd)
    self->tsd = __pthread_tsd_main;

  if (!dtor)
    dtor = nodtor;
  do {
    if (!a_cas_p(keys + j, 0, (void*)dtor)) {
      *k = j;
      return 0;
    }
  } while ((j = (j + 1) % PTHREAD_KEYS_MAX) != i);
  return EAGAIN;
}

int __pthread_key_delete(pthread_key_t k) {
  keys[k] = 0;
  return 0;
}

void __pthread_tsd_run_dtors() {
  pthread_t self = __pthread_self();
  int i, j, not_finished = self->tsd_used;
  for (j = 0; not_finished && j < PTHREAD_DESTRUCTOR_ITERATIONS; j++) {
    not_finished = 0;
    for (i = 0; i < PTHREAD_KEYS_MAX; i++) {
      if (self->tsd[i] && keys[i]) {
        void* tmp = self->tsd[i];
        self->tsd[i] = 0;
        keys[i](tmp);
        not_finished = 1;
      }
    }
  }
}

weak_alias(__pthread_key_delete, pthread_key_delete);
weak_alias(__pthread_key_create, pthread_key_create);