blob: b71bbad9a69d176f3f721c6a26367759104caf9f [file] [log] [blame]
// Copyright 2017 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package pprof
import (
"context"
"unsafe"
)
// runtime_setProfLabel is defined in runtime/proflabel.go.
func runtime_setProfLabel(labels unsafe.Pointer)
// runtime_getProfLabel is defined in runtime/proflabel.go.
func runtime_getProfLabel() unsafe.Pointer
// SetGoroutineLabels sets the current goroutine's labels to match ctx.
// A new goroutine inherits the labels of the goroutine that created it.
// This is a lower-level API than Do, which should be used instead when possible.
func SetGoroutineLabels(ctx context.Context) {
ctxLabels, _ := ctx.Value(labelContextKey{}).(*labelMap)
runtime_setProfLabel(unsafe.Pointer(ctxLabels))
}
// Do calls f with a copy of the parent context with the
// given labels added to the parent's label map.
// Goroutines spawned while executing f will inherit the augmented label-set.
// Each key/value pair in labels is inserted into the label map in the
// order provided, overriding any previous value for the same key.
// The augmented label map will be set for the duration of the call to f
// and restored once f returns.
func Do(ctx context.Context, labels LabelSet, f func(context.Context)) {
defer SetGoroutineLabels(ctx)
ctx = WithLabels(ctx, labels)
SetGoroutineLabels(ctx)
f(ctx)
}