diff options
Diffstat (limited to 'libgo/go/runtime/pprof/internal/protopprof/protopprof.go')
-rw-r--r-- | libgo/go/runtime/pprof/internal/protopprof/protopprof.go | 105 |
1 files changed, 105 insertions, 0 deletions
diff --git a/libgo/go/runtime/pprof/internal/protopprof/protopprof.go b/libgo/go/runtime/pprof/internal/protopprof/protopprof.go new file mode 100644 index 00000000000..5d269c4f652 --- /dev/null +++ b/libgo/go/runtime/pprof/internal/protopprof/protopprof.go @@ -0,0 +1,105 @@ +// 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 protopprof converts the runtime's raw profile logs +// to Profile structs containing a representation of the pprof +// protocol buffer profile format. +package protopprof + +import ( + "fmt" + "os" + "runtime" + "time" + "unsafe" + + "internal/pprof/profile" +) + +// TranslateCPUProfile parses binary CPU profiling stack trace data +// generated by runtime.CPUProfile() into a profile struct. +func TranslateCPUProfile(b []byte, startTime time.Time) (*profile.Profile, error) { + const wordSize = unsafe.Sizeof(uintptr(0)) + const minRawProfile = 5 * wordSize // Need a minimum of 5 words. + if uintptr(len(b)) < minRawProfile { + return nil, fmt.Errorf("truncated profile") + } + n := int(uintptr(len(b)) / wordSize) + data := ((*[1 << 28]uintptr)(unsafe.Pointer(&b[0])))[:n:n] + period := data[3] + data = data[5:] // skip header + + // profile initialization taken from pprof tool + p := &profile.Profile{ + Period: int64(period) * 1000, + PeriodType: &profile.ValueType{Type: "cpu", Unit: "nanoseconds"}, + SampleType: []*profile.ValueType{ + {Type: "samples", Unit: "count"}, + {Type: "cpu", Unit: "nanoseconds"}, + }, + TimeNanos: int64(startTime.UnixNano()), + DurationNanos: time.Since(startTime).Nanoseconds(), + } + // Parse CPU samples from the profile. + locs := make(map[uint64]*profile.Location) + for len(b) > 0 { + if len(data) < 2 || uintptr(len(data)) < 2+data[1] { + return nil, fmt.Errorf("truncated profile") + } + count := data[0] + nstk := data[1] + if uintptr(len(data)) < 2+nstk { + return nil, fmt.Errorf("truncated profile") + } + stk := data[2 : 2+nstk] + data = data[2+nstk:] + + if count == 0 && nstk == 1 && stk[0] == 0 { + // end of data marker + break + } + + sloc := make([]*profile.Location, len(stk)) + for i, addr := range stk { + addr := uint64(addr) + // Addresses from stack traces point to the next instruction after + // each call. Adjust by -1 to land somewhere on the actual call + // (except for the leaf, which is not a call). + if i > 0 { + addr-- + } + loc := locs[addr] + if loc == nil { + loc = &profile.Location{ + ID: uint64(len(p.Location) + 1), + Address: addr, + } + locs[addr] = loc + p.Location = append(p.Location, loc) + } + sloc[i] = loc + } + p.Sample = append(p.Sample, &profile.Sample{ + Value: []int64{int64(count), int64(count) * int64(p.Period)}, + Location: sloc, + }) + } + + if runtime.GOOS == "linux" { + if err := addMappings(p); err != nil { + return nil, err + } + } + return p, nil +} + +func addMappings(p *profile.Profile) error { + // Parse memory map from /proc/self/maps + f, err := os.Open("/proc/self/maps") + if err != nil { + return err + } + defer f.Close() + return p.ParseMemoryMap(f) +} |