[En-Nut-Discussion] Thread-safe version of asctime

Harald Kipp harald.kipp at egnite.de
Wed May 7 12:50:00 CEST 2014


the recently added asctime.c contains a few comments

  Note: This function is *not* thread safe, because it uses a static
  to store the calculated values. To be safe, you must surround the call
to asctime
  _and_ the usage of the returned pointer with NutEnterCritical() and
  Provided for compatibility to std c lib.

which I think are misleading. I cannot see, at which place we have to
expect a context switch.

The problem with static buffers is still there, e.g.

  printf("%s %s", asctime(t1), asctime(t2));

will print out t2 twice and discard t1. IMHO, NutEnterCritical()
wouldn't solve this.

Furthermore I'm not sure about

static const char wday_name[][3] = {
    "Sun", "Mon", "Tue", "Wed", "Thu", "Fri", "Sat"

AFAIK, sizeof("Sun") is 4, not 3.



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