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

   1 #include "pthread_impl.h"
   2
   3 static struct pthread main_thread;
   4
   5 /* pthread_key_create.c overrides this */
   6 static const size_t dummy = 0;
   7 weak_alias(dummy, __pthread_tsd_size);
   8
   9 #undef errno
  10 static int *errno_location()
  11 {
  12         return __pthread_self()->errno_ptr;
  13 }
  14
  15 static int init_main_thread()
  16 {
  17         void *tsd = 0;
  18         if (__pthread_tsd_size) {
  19                 tsd = mmap(0, __pthread_tsd_size, PROT_READ|PROT_WRITE,
  20                         MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
  21                 if (tsd == MAP_FAILED) return -1;
  22         }
  23         main_thread.tsd = tsd;
  24         main_thread.self = &main_thread;
  25         if (__set_thread_area(&main_thread) < 0)
  26                 return -1;
  27         main_thread.errno_ptr = __errno_location();
  28         libc.errno_location = errno_location;
  29         main_thread.tid = main_thread.pid =
  30                 syscall1(__NR_set_tid_address, (long)&main_thread.tid);
  31         return 0;
  32 }
  33
  34 pthread_t pthread_self()
  35 {
  36         static int init, failed;
  37         if (!init) {
  38                 if (failed) return 0;
  39                 if (init_main_thread() < 0) failed = 1;
  40                 if (failed) return 0;
  41                 init = 1;
  42         }
  43         return __pthread_self();
  44 }