mirror of
https://github.com/autc04/Retro68.git
synced 2024-12-04 16:50:57 +00:00
94 lines
2.8 KiB
Go
94 lines
2.8 KiB
Go
// Copyright 2016 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 (
|
|
"io"
|
|
"math"
|
|
"runtime"
|
|
"strings"
|
|
)
|
|
|
|
// writeHeapProto writes the current heap profile in protobuf format to w.
|
|
func writeHeapProto(w io.Writer, p []runtime.MemProfileRecord, rate int64) error {
|
|
b := newProfileBuilder(w)
|
|
b.pbValueType(tagProfile_PeriodType, "space", "bytes")
|
|
b.pb.int64Opt(tagProfile_Period, rate)
|
|
b.pbValueType(tagProfile_SampleType, "alloc_objects", "count")
|
|
b.pbValueType(tagProfile_SampleType, "alloc_space", "bytes")
|
|
b.pbValueType(tagProfile_SampleType, "inuse_objects", "count")
|
|
b.pbValueType(tagProfile_SampleType, "inuse_space", "bytes")
|
|
|
|
values := []int64{0, 0, 0, 0}
|
|
var locs []uint64
|
|
for _, r := range p {
|
|
locs = locs[:0]
|
|
hideRuntime := true
|
|
for tries := 0; tries < 2; tries++ {
|
|
for _, addr := range r.Stack() {
|
|
// For heap profiles, all stack
|
|
// addresses are return PCs, which is
|
|
// what locForPC expects.
|
|
if hideRuntime {
|
|
if f := runtime.FuncForPC(addr); f != nil && strings.HasPrefix(f.Name(), "runtime.") {
|
|
continue
|
|
}
|
|
// Found non-runtime. Show any runtime uses above it.
|
|
hideRuntime = false
|
|
}
|
|
l := b.locForPC(addr)
|
|
if l == 0 { // runtime.goexit
|
|
continue
|
|
}
|
|
locs = append(locs, l)
|
|
}
|
|
if len(locs) > 0 {
|
|
break
|
|
}
|
|
hideRuntime = false // try again, and show all frames
|
|
}
|
|
|
|
values[0], values[1] = scaleHeapSample(r.AllocObjects, r.AllocBytes, rate)
|
|
values[2], values[3] = scaleHeapSample(r.InUseObjects(), r.InUseBytes(), rate)
|
|
var blockSize int64
|
|
if values[0] > 0 {
|
|
blockSize = values[1] / values[0]
|
|
}
|
|
b.pbSample(values, locs, func() {
|
|
if blockSize != 0 {
|
|
b.pbLabel(tagSample_Label, "bytes", "", blockSize)
|
|
}
|
|
})
|
|
}
|
|
b.build()
|
|
return nil
|
|
}
|
|
|
|
// scaleHeapSample adjusts the data from a heap Sample to
|
|
// account for its probability of appearing in the collected
|
|
// data. heap profiles are a sampling of the memory allocations
|
|
// requests in a program. We estimate the unsampled value by dividing
|
|
// each collected sample by its probability of appearing in the
|
|
// profile. heap profiles rely on a poisson process to determine
|
|
// which samples to collect, based on the desired average collection
|
|
// rate R. The probability of a sample of size S to appear in that
|
|
// profile is 1-exp(-S/R).
|
|
func scaleHeapSample(count, size, rate int64) (int64, int64) {
|
|
if count == 0 || size == 0 {
|
|
return 0, 0
|
|
}
|
|
|
|
if rate <= 1 {
|
|
// if rate==1 all samples were collected so no adjustment is needed.
|
|
// if rate<1 treat as unknown and skip scaling.
|
|
return count, size
|
|
}
|
|
|
|
avgSize := float64(size) / float64(count)
|
|
scale := 1 / (1 - math.Exp(-avgSize/float64(rate)))
|
|
|
|
return int64(float64(count) * scale), int64(float64(size) * scale)
|
|
}
|