Function dolock

localtime.c:120–120

#  if THREAD_RWLOCK
static pthread_rwlock_t locallock = PTHREAD_RWLOCK_INITIALIZER;
static int dolock(void) { return pthread_rwlock_rdlock(&locallock); }
static void dounlock(void) { pthread_rwlock_unlock(&locallock); }
#  else
static pthread_mutex_t locallock = PTHREAD_MUTEX_INITIALIZER;