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

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