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Properties

Property: completed (readonly)​

The current number of completed tasks.

Property: duration (readonly)​

The length of time (in milliseconds) since this Piscina instance was created.

Property: options (readonly)​

A copy of the options that are currently being used by this instance. This object has the same properties as the options object passed to the constructor.

Property: runTime (readonly)​

A histogram summary object summarizing the collected run times of completed tasks. All values are expressed in milliseconds.

  • runTime.average number The average run time of all tasks
  • runTime.mean number The mean run time of all tasks
  • runTime.stddev number The standard deviation of collected run times
  • runTime.min number The fastest recorded run time
  • runTime.max number The slowest recorded run time

All properties following the pattern p{N} where N is a number (e.g. p1, p99) represent the percentile distributions of run time observations. For example, p99 is the 99th percentile indicating that 99% of the observed run times were faster or equal to the given value.

{
  average: 1880.25,
  mean: 1880.25,
  stddev: 1.93,
  min: 1877,
  max: 1882.0190887451172,
  p0_001: 1877,
  p0_01: 1877,
  p0_1: 1877,
  p1: 1877,
  p2_5: 1877,
  p10: 1877,
  p25: 1877,
  p50: 1881,
  p75: 1881,
  p90: 1882,
  p97_5: 1882,
  p99: 1882,
  p99_9: 1882,
  p99_99: 1882,
  p99_999: 1882
}

Property: threads (readonly)​

An Array of the Worker instances used by this pool.

Property: queueSize (readonly)​

The current number of tasks waiting to be assigned to a Worker thread.

Property: needsDrain (readonly)​

Boolean value that specifies whether the capacity of the pool has been exceeded by the number of tasks submitted.

This property is helpful to make decisions towards creating backpressure over the number of tasks submitted to the pool.

Property: utilization (readonly)​

A point-in-time ratio comparing the approximate total mean run time of completed tasks to the total runtime capacity of the pool.

A pools runtime capacity is determined by multiplying the duration by the options.maxThread count. This provides an absolute theoretical maximum aggregate compute time that the pool would be capable of.

The approximate total mean run time is determined by multiplying the mean run time of all completed tasks by the total number of completed tasks. This number represents the approximate amount of time the pool as been actively processing tasks.

The utilization is then calculated by dividing the approximate total mean run time by the capacity, yielding a fraction between 0 and 1.

Property: waitTime (readonly)​

A histogram summary object summarizing the collected times tasks spent waiting in the queue. All values are expressed in milliseconds.

  • waitTime.average number The average wait time of all tasks
  • waitTime.mean number The mean wait time of all tasks
  • waitTime.stddev number The standard deviation of collected wait times
  • waitTime.min number The fastest recorded wait time
  • waitTime.max number The longest recorded wait time

All properties following the pattern p{N} where N is a number (e.g. p1, p99) represent the percentile distributions of wait time observations. For example, p99 is the 99th percentile indicating that 99% of the observed wait times were faster or equal to the given value.

{
  average: 1880.25,
  mean: 1880.25,
  stddev: 1.93,
  min: 1877,
  max: 1882.0190887451172,
  p0_001: 1877,
  p0_01: 1877,
  p0_1: 1877,
  p1: 1877,
  p2_5: 1877,
  p10: 1877,
  p25: 1877,
  p50: 1881,
  p75: 1881,
  p90: 1882,
  p97_5: 1882,
  p99: 1882,
  p99_9: 1882,
  p99_99: 1882,
  p99_999: 1882
}