runtime.go

     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  	"runtime"
    10  	"unsafe"
    11  )
    12  
    13  // runtime_FrameStartLine is defined in runtime/symtab.go.
    14  //
    15  //go:noescape
    16  func runtime_FrameStartLine(f *runtime.Frame) int
    17  
    18  // runtime_FrameSymbolName is defined in runtime/symtab.go.
    19  //
    20  //go:noescape
    21  func runtime_FrameSymbolName(f *runtime.Frame) string
    22  
    23  // runtime_expandFinalInlineFrame is defined in runtime/symtab.go.
    24  func runtime_expandFinalInlineFrame(stk []uintptr) []uintptr
    25  
    26  // runtime_setProfLabel is defined in runtime/proflabel.go.
    27  func runtime_setProfLabel(labels unsafe.Pointer)
    28  
    29  // runtime_getProfLabel is defined in runtime/proflabel.go.
    30  func runtime_getProfLabel() unsafe.Pointer
    31  
    32  // SetGoroutineLabels sets the current goroutine's labels to match ctx.
    33  // A new goroutine inherits the labels of the goroutine that created it.
    34  // This is a lower-level API than [Do], which should be used instead when possible.
    35  func SetGoroutineLabels(ctx context.Context) {
    36  	ctxLabels, _ := ctx.Value(labelContextKey{}).(*labelMap)
    37  	runtime_setProfLabel(unsafe.Pointer(ctxLabels))
    38  }
    39  
    40  // Do calls f with a copy of the parent context with the
    41  // given labels added to the parent's label map.
    42  // Goroutines spawned while executing f will inherit the augmented label-set.
    43  // Each key/value pair in labels is inserted into the label map in the
    44  // order provided, overriding any previous value for the same key.
    45  // The augmented label map will be set for the duration of the call to f
    46  // and restored once f returns.
    47  func Do(ctx context.Context, labels LabelSet, f func(context.Context)) {
    48  	defer SetGoroutineLabels(ctx)
    49  	ctx = WithLabels(ctx, labels)
    50  	SetGoroutineLabels(ctx)
    51  	f(ctx)
    52  }
    53
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