open-consul/vendor/go.uber.org/goleak/internal/stack/stacks.go

156 lines
4.1 KiB
Go
Raw Normal View History

// Copyright (c) 2017 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package stack
import (
"bufio"
"bytes"
"fmt"
"io"
"runtime"
"strconv"
"strings"
)
const _defaultBufferSize = 64 * 1024 // 64 KiB
// Stack represents a single Goroutine's stack.
type Stack struct {
id int
state string
firstFunction string
fullStack *bytes.Buffer
}
// ID returns the goroutine ID.
func (s Stack) ID() int {
return s.id
}
// State returns the Goroutine's state.
func (s Stack) State() string {
return s.state
}
// Full returns the full stack trace for this goroutine.
func (s Stack) Full() string {
return s.fullStack.String()
}
// FirstFunction returns the name of the first function on the stack.
func (s Stack) FirstFunction() string {
return s.firstFunction
}
func (s Stack) String() string {
return fmt.Sprintf(
"Goroutine %v in state %v, with %v on top of the stack:\n%s",
s.id, s.state, s.firstFunction, s.Full())
}
func getStacks(all bool) []Stack {
var stacks []Stack
var curStack *Stack
stackReader := bufio.NewReader(bytes.NewReader(getStackBuffer(all)))
for {
line, err := stackReader.ReadString('\n')
if err == io.EOF {
break
}
if err != nil {
// We're reading using bytes.NewReader which should never fail.
panic("bufio.NewReader failed on a fixed string")
}
// If we see the goroutine header, start a new stack.
isFirstLine := false
if strings.HasPrefix(line, "goroutine ") {
// flush any previous stack
if curStack != nil {
stacks = append(stacks, *curStack)
}
id, goState := parseGoStackHeader(line)
curStack = &Stack{
id: id,
state: goState,
fullStack: &bytes.Buffer{},
}
isFirstLine = true
}
curStack.fullStack.WriteString(line)
if !isFirstLine && curStack.firstFunction == "" {
curStack.firstFunction = parseFirstFunc(line)
}
}
if curStack != nil {
stacks = append(stacks, *curStack)
}
return stacks
}
// All returns the stacks for all running goroutines.
func All() []Stack {
return getStacks(true)
}
// Current returns the stack for the current goroutine.
func Current() Stack {
return getStacks(false)[0]
}
func getStackBuffer(all bool) []byte {
for i := _defaultBufferSize; ; i *= 2 {
buf := make([]byte, i)
if n := runtime.Stack(buf, all); n < i {
return buf[:n]
}
}
}
func parseFirstFunc(line string) string {
line = strings.TrimSpace(line)
if idx := strings.LastIndex(line, "("); idx > 0 {
return line[:idx]
}
panic(fmt.Sprintf("function calls missing parents: %q", line))
}
// parseGoStackHeader parses a stack header that looks like:
// goroutine 643 [runnable]:\n
// And returns the goroutine ID, and the state.
func parseGoStackHeader(line string) (goroutineID int, state string) {
line = strings.TrimSuffix(line, ":\n")
parts := strings.SplitN(line, " ", 3)
if len(parts) != 3 {
panic(fmt.Sprintf("unexpected stack header format: %q", line))
}
id, err := strconv.Atoi(parts[1])
if err != nil {
panic(fmt.Sprintf("failed to parse goroutine ID: %v in line %q", parts[1], line))
}
state = strings.TrimSuffix(strings.TrimPrefix(parts[2], "["), "]")
return id, state
}