+
+if(HAVE_UNISTD_H)
+ set(CMAKE_REQUIRED_INCLUDES ${CMAKE_INCLUDE_PATH})
+ check_cxx_source_compiles(
+ "#include <unistd.h>
+ #if !defined(_POSIX_TIMERS) || (0 >= _POSIX_TIMERS)
+ #error clock_gettime is not supported
+ #endif
+
+ int main() { return 0; }
+ "
+ HAVE_CLOCK_GETTIME)
+endif(HAVE_UNISTD_H)
+
+set(RT_LIBRARY "")
+if(HAVE_CLOCK_GETTIME)
+ check_function_exists(clock_gettime CLOCK_GETTIME_IN_LIBC)
+ if(NOT CLOCK_GETTIME_IN_LIBC)
+ check_library_exists(rt clock_gettime "" HAVE_RT)
+ if(HAVE_RT)
+ set(RT_LIBRARY rt)
+ endif(HAVE_RT)
+ endif(NOT CLOCK_GETTIME_IN_LIBC)
+endif(HAVE_CLOCK_GETTIME)
+