[glib: 1/2] tests: Add some rounding tolerance in timeout test

[Sebastian Dröge <sdroege src gnome org>]

commit ff563867886585f4b48601553f820e08f1f9ac0e
Author: Philip Withnall <pwithnall endlessos org>
Date:   Fri Dec 11 12:37:26 2020 +0000

    tests: Add some rounding tolerance in timeout test
    
    Occasionally this test fails in CI with the message:
    ```
    assertion failed: (current_time / 1000000 - last_time / 1000000 == 1)
    ```
    
    The way this calculation is done at the moment, a difference of 1001ms
    between `current_time` and `last_time` can result in failure, if the
    times are close to a multiple to 1000ms.
    
    Change it to only truncate the result after doing the subtraction, and
    add a 500ms tolerance to account for scheduling delays in the test. (For
    example, the `test_func()` could be called, then descheduled before it
    gets to call `g_get_monotonic_time()`.
    
    Additionally, change the test to use `g_assert_cmpint()` so that future
    failures provide more useful debug information.
    
    Signed-off-by: Philip Withnall <pwithnall endlessos org>

 glib/tests/timeout.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)
---
diff --git a/glib/tests/timeout.c b/glib/tests/timeout.c
index fc836f312..9e4d047a6 100644
--- a/glib/tests/timeout.c
+++ b/glib/tests/timeout.c
@@ -152,11 +152,13 @@ test_func (gpointer data)
 
   /* We accept 2 on the first iteration because _add_seconds() can
    * have an initial latency of 1 second, see its documentation.
+   *
+   * Allow up to 500ms leeway for rounding and scheduling.
    */
   if (count == 0)
-    g_assert (current_time / 1000000 - last_time / 1000000 <= 2);
+    g_assert_cmpint (current_time / 1000 - last_time / 1000, <=, 2500);
   else
-    g_assert (current_time / 1000000 - last_time / 1000000 == 1);
+    g_assert_cmpint (current_time / 1000 - last_time / 1000, <=, 1500);
 
   last_time = current_time;
   count++;