# HW_HEADER_TIME_H

# ------------------

# Define HAVE_TIME_H to 1 if <time.h> is available.

AC_DEFUN([HW_HEADER_TIME_H],

[

  AC_PREREQ([2.60])dnl Older releases should work if AC_CHECK_HEADERS is used.

  AC_CHECK_HEADERS_ONCE([time.h])

])# HW_HEADER_TIME_H

# HW_LIBRT_TIMERS

# -----------------

# Set $hw_cv_librt_timers and $hw_cv_librt_timers_posix to "yes" or "no",

# respectively.  If the timer_create() function is available and

# POSIX compliant, then the system's timer_create(), timer_settime(),

# and timer_delete() functions are used. Otherwise, make sure

# the replacement functions will be built.

#

# In the case where we are cross compiling, the POSIX detection of

# the timer_create() function is skipped, and instead the usual check

# for the existence of all the timer_* functions is done using

# AC_REPLACE_FUNCS.

#

# If enable_timer_replacement=true, the replacements is forced to be built.

AC_DEFUN([HW_LIBRT_TIMERS],

[

  AC_PREREQ([2.60])dnl 2.59 should work if some AC_TYPE_* macros are replaced.

  AC_REQUIRE([HW_HEADER_TIME_H])dnl Our check evaluates HAVE_TIME_H.

  if test "xtrue" != x"$enable_timer_replacement"; then

	  AC_CHECK_FUNC([timer_create],

		[hw_cv_librt_timers=yes],

		[hw_cv_librt_timers=no])

	  AS_IF([test "$hw_cv_librt_timers" = yes],

		[AC_CACHE_CHECK([if timer_create is supported on the system],

		  [hw_cv_librt_timers_posix],

		  [AC_RUN_IFELSE(

			[AC_LANG_PROGRAM(

			  [[#if HAVE_TIME_H

			  #include <time.h>

			  #endif

              #include <errno.h>

			  static int test_timer_create()

			  {

                timer_t timerid;

                if(timer_create(CLOCK_REALTIME, NULL, &timerid) != 0)

                {

                    /* 

                      On this system, although the function is available,

                      no meaningful implementation is provided.

                    */

                    if(errno == ENOSYS)

                    {

                        return 1;

                    }

                }

                return 0;

			  }]],

			  [[return test_timer_create();]])],

			[hw_cv_librt_timers_posix=yes],

			[hw_cv_librt_timers_posix=no],

			[hw_cv_librt_timers_posix=autodetect])])],

		[hw_cv_librt_timers_posix=no])

  else

      hw_cv_librt_timers_posix=no

  fi

  # If the system does not have a POSIX timer_create(), then use

  # Check's reimplementation of the timer_* calls

  AS_IF([test "$hw_cv_librt_timers_posix" = no],

    [_HW_LIBRT_TIMERS_REPLACE])

  # If we are cross compiling, do the normal check for the

  # timer_* calls.

  AS_IF([test "$hw_cv_librt_timers_posix" = autodetect],

    [AC_REPLACE_FUNCS([timer_create timer_settime timer_delete])

     AC_CHECK_DECLS([timer_create, timer_settime, timer_delete])])

])# HW_LIBRT_TIMERS

# _HW_LIBRT_TIMERS_REPLACE

# ------------------------

# Arrange for building timer_create.c, timer_settime.c, and

# timer_delete.c.

AC_DEFUN([_HW_LIBRT_TIMERS_REPLACE],

[

  AS_IF([test "x$_hw_cv_librt_timers_replace_done" != xyes],

    [AC_LIBOBJ([timer_create])

     AC_LIBOBJ([timer_settime])

     AC_LIBOBJ([timer_delete])

    _hw_cv_librt_timers_replace_done=yes])

])# _HW_LIBRT_TIMERS_REPLACE