config/tls.m4

   1 # See if we have working TLS.  We only check to see if it compiles, and that
   2 # the resulting program actually runs, not whether the resulting TLS variables
   3 # work properly; that check is done at runtime, since we can run binaries
   4 # compiled with __thread on systems without TLS.
   5 AC_DEFUN([LXC_CHECK_TLS],
   6 [
   7     AC_MSG_CHECKING(for TLS)
   8     AC_COMPILE_IFELSE([AC_LANG_SOURCE([[ static __thread int val; int main() { return 0; } ]])],[have_tls=yes],[have_tls=no],[have_tls=no ])
   9     AC_MSG_RESULT($have_tls)
  10     if test "$have_tls" = "yes"; then
  11         AC_DEFINE([HAVE_TLS],[1],[Define if the compiler supports __thread])
  12         AC_DEFINE([thread_local],[__thread],[Define to the compiler TLS keyword])
  13     fi
  14 ])