package trace

Import Path
	runtime/trace (on and

Dependency Relation
	imports 7 packages, and imported by 2 packages

Involved Source Files
	d-> trace.go

Exported Type Names

type Region (struct) Region is a region of code whose execution time interval is traced. (*T) End() func StartRegion(ctx context.Context, regionType string) *Region
type Task (struct) Task is a data type for tracing a user-defined, logical operation. (*T) End() func NewTask(pctx context.Context, taskType string) (ctx context.Context, task *Task)
Exported Values
func IsEnabled() bool IsEnabled reports whether tracing is enabled. The information is advisory only. The tracing status may have changed by the time this function returns.
func Log(ctx context.Context, category, message string) Log emits a one-off event with the given category and message. Category can be empty and the API assumes there are only a handful of unique categories in the system.
func Logf(ctx context.Context, category, format string, args ...interface{}) Logf is like Log, but the value is formatted using the specified format spec.
func NewTask(pctx context.Context, taskType string) (ctx context.Context, task *Task) NewTask creates a task instance with the type taskType and returns it along with a Context that carries the task. If the input context contains a task, the new task is its subtask. The taskType is used to classify task instances. Analysis tools like the Go execution tracer may assume there are only a bounded number of unique task types in the system. The returned end function is used to mark the task's end. The trace tool measures task latency as the time between task creation and when the end function is called, and provides the latency distribution per task type. If the end function is called multiple times, only the first call is used in the latency measurement. ctx, task := trace.NewTask(ctx, "awesomeTask") trace.WithRegion(ctx, "preparation", prepWork) // preparation of the task go func() { // continue processing the task in a separate goroutine. defer task.End() trace.WithRegion(ctx, "remainingWork", remainingWork) }()
func Start(w io.Writer) error Start enables tracing for the current program. While tracing, the trace will be buffered and written to w. Start returns an error if tracing is already enabled.
func StartRegion(ctx context.Context, regionType string) *Region StartRegion starts a region and returns a function for marking the end of the region. The returned Region's End function must be called from the same goroutine where the region was started. Within each goroutine, regions must nest. That is, regions started after this region must be ended before this region can be ended. Recommended usage is defer trace.StartRegion(ctx, "myTracedRegion").End()
func Stop() Stop stops the current tracing, if any. Stop only returns after all the writes for the trace have completed.
func WithRegion(ctx context.Context, regionType string, fn func()) WithRegion starts a region associated with its calling goroutine, runs fn, and then ends the region. If the context carries a task, the region is associated with the task. Otherwise, the region is attached to the background task. The regionType is used to classify regions, so there should be only a handful of unique region types.