src/hotspot/share/utilities/numberSeq.cpp

*** 108,10 ***
--- 108,36 ---
    double var = dvariance();
    guarantee( var >= 0.0, "variance should not be negative" );
    return sqrt(var);
  }
  
+ void AbsSeq::merge(AbsSeq& abs2, bool clear_this) {
+ 
+   if (num() == 0) return;  // nothing to do
+ 
+   abs2._num += _num;
+   abs2._sum += _sum;
+   abs2._sum_of_squares += _sum_of_squares;
+ 
+   // Decaying stats need a bit more thought
+   assert(abs2._alpha == _alpha, "Caution: merge incompatible?");
+   // Until JDK-8298902 is fixed, we taint the decaying statistics
+   if (abs2._davg != NAN) {
+     abs2._davg = NAN;
+     abs2._dvariance = NAN;
+   }
+ 
+   if (clear_this) {
+     _num = 0;
+     _sum = 0;
+     _sum_of_squares = 0;
+     _davg = 0;
+     _dvariance = 0;
+   }
+ }
+ 
+ 
  NumberSeq::NumberSeq(double alpha) :
    AbsSeq(alpha), _last(0.0), _maximum(0.0) {
  }
  
  bool NumberSeq::check_nums(NumberSeq *total, int n, NumberSeq **parts) {

*** 135,10 ***
--- 161,26 ---
    _sum += val;
    _sum_of_squares += val * val;
    ++_num;
  }
  
+ void NumberSeq::merge(NumberSeq& nseq2, bool clear_this) {
+ 
+   if (num() == 0) return;  // nothing to do
+ 
+   nseq2._last = _last;   // this is newer than that
+   nseq2._maximum = MAX2(_maximum, nseq2._maximum);
+ 
+   AbsSeq::merge(nseq2, clear_this);
+ 
+   if (clear_this) {
+     _last = 0;
+     _maximum = 0;
+     assert(num() == 0, "Not cleared");
+   }
+ }
+ 
  
  TruncatedSeq::TruncatedSeq(int length, double alpha):
    AbsSeq(alpha), _length(length), _next(0) {
    _sequence = NEW_C_HEAP_ARRAY(double, _length, mtInternal);
    for (int i = 0; i < _length; ++i)