Test 32bit time in tracked_object

Be sure it is disabled or enabled as expected.

Be sure it is using the same basic function as TimeTicks.

r=rtenneti
Review URL: http://codereview.chromium.org/8437018

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@108228 0039d316-1c4b-4281-b951-d872f2087c98

base/tracked_objects_unittest.cc

@@ -605,4 +605,102 @@ TEST_F(TrackedObjectsTest, DifferentLives) {
   EXPECT_EQ(one_line_result, json);
 }
 
+TEST_F(TrackedObjectsTest, TrackedTimerMilliseconds) {
+  // First make sure we basicallly transfer simple milliseconds values as
+  // expected.  Most critically, things should not become null.
+  int32 kSomeMilliseconds = 243;  // Some example times.
+  int64 kReallyBigMilliseconds = (1LL << 35) + kSomeMilliseconds;
+
+  TrackedTime some = TrackedTime() +
+      Duration::FromMilliseconds(kSomeMilliseconds);
+  EXPECT_EQ(kSomeMilliseconds, (some - TrackedTime()).InMilliseconds());
+  EXPECT_FALSE(some.is_null());
+
+  // Now create a big time, to check that it is wrapped modulo 2^32.
+  base::TimeTicks big = base::TimeTicks() +
+      base::TimeDelta::FromMilliseconds(kReallyBigMilliseconds);
+  EXPECT_EQ(kReallyBigMilliseconds, (big - base::TimeTicks()).InMilliseconds());
+
+  TrackedTime wrapped_big(big);
+#if defined(USE_FAST_TIME_CLASS_FOR_DURATION_CALCULATIONS)
+  // Expect wrapping at 32 bits.
+  EXPECT_EQ(kSomeMilliseconds, (wrapped_big - TrackedTime()).InMilliseconds());
+#else  // !USE_FAST_TIME_CLASS_FOR_DURATION_CALCULATIONS)
+  // Expect no wrapping at 32 bits.
+  EXPECT_EQ(kReallyBigMilliseconds,
+            (wrapped_big - TrackedTime()).InMilliseconds());
+#endif  // USE_FAST_TIME_CLASS_FOR_DURATION_CALCULATIONS)
+}
+
+TEST_F(TrackedObjectsTest, TrackedTimerDuration) {
+  int kFirstMilliseconds = 793;
+  int kSecondMilliseconds = 14889;
+
+  Duration first = Duration::FromMilliseconds(kFirstMilliseconds);
+  Duration second = Duration::FromMilliseconds(kSecondMilliseconds);
+
+  EXPECT_EQ(kFirstMilliseconds, first.InMilliseconds());
+  EXPECT_EQ(kSecondMilliseconds, second.InMilliseconds());
+
+  Duration sum = first + second;
+  EXPECT_EQ(kFirstMilliseconds + kSecondMilliseconds, sum.InMilliseconds());
+}
+
+TEST_F(TrackedObjectsTest, TrackedTimerVsTimeTicks) {
+  // Make sure that our 32 bit timer is aligned with the TimeTicks() timer.
+
+  // First get a 64 bit timer (which should not be null).
+  base::TimeTicks ticks_before = base::TimeTicks::Now();
+  EXPECT_FALSE(ticks_before.is_null());
+
+  // Then get a 32 bit timer that can be be null when it wraps.
+  TrackedTime now = TrackedTime::Now();
+
+  // Then get a bracketing time.
+  base::TimeTicks ticks_after = base::TimeTicks::Now();
+  EXPECT_FALSE(ticks_after.is_null());
+
+  // Now make sure that we bracketed our tracked time nicely.
+  Duration before = now - TrackedTime(ticks_before);
+  EXPECT_LE(0, before.InMilliseconds());
+  Duration after = now - TrackedTime(ticks_after);
+  EXPECT_GE(0, after.InMilliseconds());
+}
+
+TEST_F(TrackedObjectsTest, TrackedTimerDisabled) {
+  // Check to be sure disabling the collection of data induces a null time
+  // (which we know will return much faster).
+  if (!ThreadData::InitializeAndSetTrackingStatus(false))
+    return;
+  // Since we disabled tracking, we should get a null response.
+  TrackedTime track_now = ThreadData::Now();
+  EXPECT_TRUE(track_now.is_null());
+}
+
+TEST_F(TrackedObjectsTest, TrackedTimerEnabled) {
+  if (!ThreadData::InitializeAndSetTrackingStatus(true))
+    return;
+  // Make sure that when we enable tracking, we get a real timer result.
+
+  // First get a 64 bit timer (which should not be null).
+  base::TimeTicks ticks_before = base::TimeTicks::Now();
+  EXPECT_FALSE(ticks_before.is_null());
+
+  // Then get a 32 bit timer that can be null when it wraps.
+  // Crtical difference from  the TrackedTimerVsTimeTicks test, is that we use
+  // ThreadData::Now().  It can sometimes return the null time.
+  TrackedTime now = ThreadData::Now();
+
+  // Then get a bracketing time.
+  base::TimeTicks ticks_after = base::TimeTicks::Now();
+  EXPECT_FALSE(ticks_after.is_null());
+
+  // Now make sure that we bracketed our tracked time nicely.
+  Duration before = now - TrackedTime(ticks_before);
+  EXPECT_LE(0, before.InMilliseconds());
+  Duration after = now - TrackedTime(ticks_after);
+  EXPECT_GE(0, after.InMilliseconds());
+}
+
+
 }  // namespace tracked_objects