Accumulator Class

An Accumulator object is created by an Event object to accumulate performance data. An Accumulator depends on the 64-bit counter maintained by their parent Event object, which is used for computing the average accumulation value over some time. Each Accumulator maintains four values: a sum, a sum of squares, a min, and a max. The min and max values are reset at the beginning of each aggregation interval. If they are not reset each time, they become meaningless over the lifetime of the application, but the two sums are cumulative over the life of the Accumulator and are initialized to zero.

The recordValue member function can be used to change the value of the Accumulator, and optionally increment the value of the associated Event counter as well. The associated Event can be determined with the getEvent member function.

For more information about the creation and usage of Accumulators, see the topics in the section Recording Values with Accumulators.