1 // Copyright 2017 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package pprof 6 7 import ( 8 "context" 9 "unsafe" 10 ) 11 12 // runtime_expandFinalInlineFrame is defined in runtime/symtab.go. 13 func runtime_expandFinalInlineFrame(stk []uintptr) []uintptr 14 15 // runtime_setProfLabel is defined in runtime/proflabel.go. 16 func runtime_setProfLabel(labels unsafe.Pointer) 17 18 // runtime_getProfLabel is defined in runtime/proflabel.go. 19 func runtime_getProfLabel() unsafe.Pointer 20 21 // SetGoroutineLabels sets the current goroutine's labels to match ctx. 22 // A new goroutine inherits the labels of the goroutine that created it. 23 // This is a lower-level API than Do, which should be used instead when possible. 24 func SetGoroutineLabels(ctx context.Context) { 25 ctxLabels, _ := ctx.Value(labelContextKey{}).(*labelMap) 26 runtime_setProfLabel(unsafe.Pointer(ctxLabels)) 27 } 28 29 // Do calls f with a copy of the parent context with the 30 // given labels added to the parent's label map. 31 // Goroutines spawned while executing f will inherit the augmented label-set. 32 // Each key/value pair in labels is inserted into the label map in the 33 // order provided, overriding any previous value for the same key. 34 // The augmented label map will be set for the duration of the call to f 35 // and restored once f returns. 36 func Do(ctx context.Context, labels LabelSet, f func(context.Context)) { 37 defer SetGoroutineLabels(ctx) 38 ctx = WithLabels(ctx, labels) 39 SetGoroutineLabels(ctx) 40 f(ctx) 41 } 42