grunning

Documentation

Overview

Package grunning is a library that's able to retrieve on-CPU running time for individual goroutines. It relies on using a patched Go and provides a primitive for fine-grained CPU attribution and control. See #82356 for more details.

Index

• func Difference(a, b time.Duration) time.Duration
• func Elapsed(start, end time.Duration) time.Duration
• func Supported() bool
• func Time() time.Duration

Functions

func Difference

func Difference(a, b time.Duration) time.Duration

Difference is a helper function to compute the absolute difference between two durations.

func Elapsed

func Elapsed(start, end time.Duration) time.Duration

Elapsed returns the running time spent doing some piece of work, with grunning.Time() measurements from the start and end.

NB: This only exists due to grunning.Time()'s non-monotonicity, a bug in our runtime patch: https://github.com/cockroachdb/cockroachdb-parser/issues/95529. We can get rid of this, keeping just grunning.Difference(), if that bug is fixed. The bug results in slight {over,under}-estimation of the running time (the latter breaking monotonicity), but is livable with our current uses of this library.

func Supported

func Supported() bool

Supported returns true iff per-goroutine running time is available in this build. We use a patched Go runtime for all platforms officially supported for CRDB when built using Bazel.

func Time

func Time() time.Duration

Time returns the time spent by the current goroutine in the running state.