Fix windows test to also pass under wine

It looks as if the default timer resolution for applications running under wine
is different than Windows so just test that the minimum timer resolution is
below a certain amount rather than checking before and after calling
timeBeginPeriod

diff --git a/libs/pbd/test/windows_timer_utils_test.cc b/libs/pbd/test/windows_timer_utils_test.cc
index 1566f37d960fc62d4d48df9f9ac71b96961eb24b..cd2ba5904001040cc59180041f90505eab3ee3da 100644 (file)
--- a/libs/pbd/test/windows_timer_utils_test.cc
+++ b/libs/pbd/test/windows_timer_utils_test.cc
@@ -79,11 +79,13 @@ void get_sleep_granularity(uint32_t& min_elapsed,
                uint32_t current_time_ms = timeGetTime();
                uint32_t elapsed = current_time_ms - last_time_ms;
                cout << "Sleep elapsed = " << elapsed << endl;
-               min_elapsed = std::min (min_elapsed, current_time_ms - last_time_ms);
-               max_elapsed = std::max (max_elapsed, current_time_ms - last_time_ms);
+               min_elapsed = std::min (min_elapsed, elapsed);
+               max_elapsed = std::max (max_elapsed, elapsed);
                total_elapsed += elapsed;
                last_time_ms = current_time_ms;
        }
+       // the rounding here doesn't matter, we aren't interested in
+       // accurate measurements
        avg_elapsed = total_elapsed / count;
 }
 
@@ -119,11 +121,6 @@ test_sleep_granularity (const std::string& test_name, uint32_t& sleep_avg_elapse
 
 } // namespace
 
-/**
- * This test will not succeed if the current system wide timer resolution is
- * already at the minimum but in most cases it won't be and it will test
- * whether setting the minimum timer resolution is successful.
- */
 void
 WindowsTimerUtilsTest::testMMTimers ()
 {
@@ -146,15 +143,19 @@ WindowsTimerUtilsTest::testMMTimers ()
 
        test_tgt_granularity ("Minimum Timer Resolution", avg_min_res_tgt_elapsed);
 
-       // test that it is less than original granularity
-       CPPUNIT_ASSERT (avg_min_res_tgt_elapsed < avg_orig_res_tgt_elapsed);
+       // test that it the avg granularity is the same as miniumum resolution
+       CPPUNIT_ASSERT (avg_min_res_tgt_elapsed == 1);
 
        uint32_t avg_min_res_sleep_elapsed = 0;
 
        test_sleep_granularity ("Minimum Timer Resolution", avg_min_res_sleep_elapsed);
 
-       // test that it is less than original granularity
-       CPPUNIT_ASSERT (avg_min_res_sleep_elapsed < avg_orig_res_sleep_elapsed);
+       // In a heavily loaded system and without running this test with raised
+       // scheduling priority we can't assume that the sleep granularity is the
+       // same as the minimum timer resolution so give it 1ms of slack, if it is
+       // greater than that then there likely is a problem that needs
+       // investigating.
+       CPPUNIT_ASSERT (avg_min_res_sleep_elapsed <= 2);
 
        CPPUNIT_ASSERT (PBD::MMTIMERS::reset_resolution());