/*
 * glibc-2.0 libdl is not MT safe.  If you are building with any glibc,
 * chances are you might want to run the generated bits against glibc-2.0
 * libdl.so, so always use locking for any version of glibc.
 */

void* os::dll_lookup(void* handle, const char* name) {

  {- -------------------------------------------
  (1) dlsym() を呼び出す.
      (なお, glibc-2.0 の libdl は MT safe ではないのでロックを取っているとのこと)
      ---------------------------------------- -}

      pthread_mutex_lock(&dl_mutex);
      void* res = dlsym(handle, name);
      pthread_mutex_unlock(&dl_mutex);
      return res;
    }