nsz Git - musl/blob - src/thread/pthread_key_create.c

   1 #include "pthread_impl.h"
   2
   3 volatile size_t __pthread_tsd_size = sizeof(void *) * PTHREAD_KEYS_MAX;
   4 void *__pthread_tsd_main[PTHREAD_KEYS_MAX] = { 0 };
   5
   6 static void (*volatile keys[PTHREAD_KEYS_MAX])(void *);
   7
   8 static void nodtor(void *dummy)
   9 {
  10 }
  11
  12 int __pthread_key_create(pthread_key_t *k, void (*dtor)(void *))
  13 {
  14         unsigned i = (uintptr_t)&k / 16 % PTHREAD_KEYS_MAX;
  15         unsigned j = i;
  16         pthread_t self = __pthread_self();
  17
  18         /* This can only happen in the main thread before
  19          * pthread_create has been called. */
  20         if (!self->tsd) self->tsd = __pthread_tsd_main;
  21
  22         if (!dtor) dtor = nodtor;
  23         do {
  24                 if (!a_cas_p(keys+j, 0, (void *)dtor)) {
  25                         *k = j;
  26                         return 0;
  27                 }
  28         } while ((j=(j+1)%PTHREAD_KEYS_MAX) != i);
  29         return EAGAIN;
  30 }
  31
  32 int __pthread_key_delete(pthread_key_t k)
  33 {
  34         keys[k] = 0;
  35         return 0;
  36 }
  37
  38 void __pthread_tsd_run_dtors()
  39 {
  40         pthread_t self = __pthread_self();
  41         int i, j, not_finished = self->tsd_used;
  42         for (j=0; not_finished && j<PTHREAD_DESTRUCTOR_ITERATIONS; j++) {
  43                 not_finished = 0;
  44                 for (i=0; i<PTHREAD_KEYS_MAX; i++) {
  45                         if (self->tsd[i] && keys[i]) {
  46                                 void *tmp = self->tsd[i];
  47                                 self->tsd[i] = 0;
  48                                 keys[i](tmp);
  49                                 not_finished = 1;
  50                         }
  51                 }
  52         }
  53 }
  54
  55 weak_alias(__pthread_key_delete, pthread_key_delete);
  56 weak_alias(__pthread_key_create, pthread_key_create);