test/hotspot/gtest/gc/g1/test_g1Predictions.cpp

rev 56997 : [mq]: 8227434-g1-predictions-overflow

*** 24,33 ****
--- 24,35 ----
  
  #include "precompiled.hpp"
  #include "gc/g1/g1Predictions.hpp"
  #include "unittest.hpp"
  
+ #include "utilities/ostream.hpp"
+ 
  static const double epsilon = 1e-6;
  
  // Some basic formula tests with confidence = 0.0
  TEST_VM(G1Predictions, basic_predictions) {
    G1Predictions predictor(0.0);
*** 94,98 ****
--- 96,148 ----
    s.add(0.2);
    s.add(2.0);
    double p4 = predictor.get_new_prediction(&s);
    ASSERT_GT(p4, p3) << "Fourth prediction must be greater than third";
  }
+ 
+ // Some tests to verify bounding between [0 .. 1]
+ TEST_VM(G1Predictions, unit_predictions) {
+   G1Predictions predictor(0.5);
+   TruncatedSeq s;
+ 
+   double p0 = predictor.get_new_unit_prediction(&s);
+   ASSERT_LT(p0, epsilon) << "Initial prediction of empty sequence must be 0.0";
+ 
+   s.add(100.0);
+   double p1 = predictor.get_new_unit_prediction(&s);
+   ASSERT_NEAR(p1, 1.0, epsilon);
+ 
+   // Feed the sequence additional positive values to test the high bound.
+   for (int i = 0; i < 3; i++) {
+     s.add(2.0);
+   }
+   ASSERT_NEAR(predictor.get_new_unit_prediction(&s), 1.0, epsilon);
+ 
+   // Feed the sequence additional large negative value to test the low bound.
+   for (int i = 0; i < 4; i++) {
+     s.add(-200.0);
+   }
+   ASSERT_NEAR(predictor.get_new_unit_prediction(&s), 0.0, epsilon);
+ }
+ 
+ // Some tests to verify bounding between [0 .. +inf]
+ TEST_VM(G1Predictions, lower_bound_zero_predictions) {
+   G1Predictions predictor(0.5);
+   TruncatedSeq s;
+ 
+   double p0 = predictor.get_new_lower_zero_bound_prediction(&s);
+   ASSERT_LT(p0, epsilon) << "Initial prediction of empty sequence must be 0.0";
+ 
+   s.add(100.0);
+   // Feed the sequence additional positive values to see that the high bound is not
+   // bounded by e.g. 1.0
+   for (int i = 0; i < 3; i++) {
+     s.add(2.0);
+   }
+   ASSERT_GT(predictor.get_new_lower_zero_bound_prediction(&s), 1.0);
+ 
+   // Feed the sequence additional large negative value to test the low bound.
+   for (int i = 0; i < 4; i++) {
+     s.add(-200.0);
+   }
+   ASSERT_NEAR(predictor.get_new_lower_zero_bound_prediction(&s), 0.0, epsilon);
+ }