make sleep test automated check with system_clock

src/tests/system/CMakeLists.txt

@@ -1,5 +1,5 @@
 add_executable(test_sleep test_sleep.f90)
 target_link_libraries(test_sleep fortran_stdlib)
 
-add_test(NAME Sleep COMMAND $<TARGET_FILE:test_sleep> 650)
-set_tests_properties(Sleep PROPERTIES TIMEOUT 5)
+add_test(NAME Sleep COMMAND $<TARGET_FILE:test_sleep> 350)
+set_tests_properties(Sleep PROPERTIES TIMEOUT 1)

src/tests/system/test_sleep.f90

@@ -1,18 +1,33 @@
 program test_sleep
-
+use, intrinsic :: iso_fortran_env, only : int64, real64
 use stdlib_experimental_system, only : sleep
 
 implicit none
 
 integer :: ierr, millisec
 character(8) :: argv
+integer(int64) :: tic, toc, trate
+real(real64) :: t_ms
+
+call system_clock(count_rate=trate)
 
 millisec = 780
 call get_command_argument(1, argv, status=ierr)
 if (ierr==0) read(argv,*) millisec
 
 if (millisec<0) millisec=0
 
+call system_clock(count=tic)
 call sleep(millisec)
+call system_clock(count=toc)
+
+t_ms = (toc-tic) * 1000._real64 / trate
+
+if (millisec > 0) then
+  if (t_ms < 0.5 * millisec) error stop 'actual sleep time was too short'
+  if (t_ms > 2 * millisec) error stop 'actual sleep time was too long'
+endif
+
+print '(A,F8.3)', 'OK: test_sleep: slept for (ms): ',t_ms
 
 end program