safing-portmaster/service/mgr/worker_info.go
2024-08-28 11:55:40 +02:00

389 lines
9.4 KiB
Go

package mgr
import (
"bytes"
"errors"
"fmt"
"io"
"reflect"
"runtime"
"slices"
"strconv"
"strings"
"text/tabwriter"
"github.com/maruel/panicparse/v2/stack"
)
// WorkerInfoModule is used for interface checks on modules.
type WorkerInfoModule interface {
WorkerInfo(s *stack.Snapshot) (*WorkerInfo, error)
}
func (m *Manager) registerWorker(w *WorkerCtx) {
m.workersLock.Lock()
defer m.workersLock.Unlock()
// Iterate forwards over the ring buffer.
end := (m.workersIndex - 1 + len(m.workers)) % len(m.workers)
for {
// Check if entry is available.
if m.workers[m.workersIndex] == nil {
m.workers[m.workersIndex] = w
return
}
// Check if we checked the whole ring buffer.
if m.workersIndex == end {
break
}
// Go to next index.
m.workersIndex = (m.workersIndex + 1) % len(m.workers)
}
// Increase ring buffer.
newRingBuf := make([]*WorkerCtx, len(m.workers)*4)
copy(newRingBuf, m.workers)
// Add new entry.
m.workersIndex = len(m.workers)
newRingBuf[m.workersIndex] = w
m.workersIndex++
// Switch to new ring buffer.
m.workers = newRingBuf
}
func (m *Manager) unregisterWorker(w *WorkerCtx) {
m.workersLock.Lock()
defer m.workersLock.Unlock()
// Iterate backwards over the ring buffer.
i := m.workersIndex
end := (i + 1) % len(m.workers)
for {
// Check if entry is the one we want to remove.
if m.workers[i] == w {
m.workers[i] = nil
return
}
// Check if we checked the whole ring buffer.
if i == end {
break
}
// Go to next index.
i = (i - 1 + len(m.workers)) % len(m.workers)
}
}
// WorkerInfo holds status information about a managers workers.
type WorkerInfo struct {
Running int
Waiting int
Other int
Missing int
Workers []*WorkerInfoDetail
}
// WorkerInfoDetail holds status information about a single worker.
type WorkerInfoDetail struct {
Count int
State string
Mgr string
Name string
Func string
CurrentLine string
ExtraInfo string
}
// WorkerInfo returns status information for all running workers of this manager.
func (m *Manager) WorkerInfo(s *stack.Snapshot) (*WorkerInfo, error) {
m.workersLock.Lock()
defer m.workersLock.Unlock()
var err error
if s == nil {
s, _, err = stack.ScanSnapshot(bytes.NewReader(fullStack()), io.Discard, stack.DefaultOpts())
if err != nil && !errors.Is(err, io.EOF) {
return nil, fmt.Errorf("get stack: %w", err)
}
}
wi := &WorkerInfo{
Workers: make([]*WorkerInfoDetail, 0, len(m.workers)),
}
// Go through all registered workers of manager.
for _, w := range m.workers {
// Ignore empty slots.
if w == nil {
continue
}
// Setup worker detail struct.
wd := &WorkerInfoDetail{
Count: 1,
Mgr: m.name,
}
if w.workerMgr != nil {
wd.Name = w.workerMgr.name
wd.Func = getFuncName(w.workerMgr.fn)
} else {
wd.Name = w.name
wd.Func = getFuncName(w.workFunc)
}
// Search for stack of this worker.
goroutines:
for _, gr := range s.Goroutines {
for _, call := range gr.Stack.Calls {
// Check if the can find the worker function in a call stack.
fullFuncName := call.Func.ImportPath + "." + call.Func.Name
if fullFuncName == wd.Func {
wd.State = gr.State
// Find most useful line for where the goroutine currently is at.
// Cut import path prefix to domain/user, eg. github.com/safing
importPathPrefix := call.ImportPath
splitted := strings.SplitN(importPathPrefix, "/", 3)
if len(splitted) == 3 {
importPathPrefix = splitted[0] + "/" + splitted[1] + "/"
}
// Find "last" call within that import path prefix.
for _, call = range gr.Stack.Calls {
if strings.HasPrefix(call.ImportPath, importPathPrefix) {
wd.CurrentLine = call.ImportPath + "/" + call.SrcName + ":" + strconv.Itoa(call.Line)
break
}
}
// Fall back to last call if no better line was found.
if wd.CurrentLine == "" {
wd.CurrentLine = gr.Stack.Calls[0].ImportPath + "/" + gr.Stack.Calls[0].SrcName + ":" + strconv.Itoa(gr.Stack.Calls[0].Line)
}
// Add some extra info in some cases.
if wd.State == "sleep" { //nolint:goconst
wd.ExtraInfo = gr.SleepString()
}
break goroutines
}
}
}
// Summarize and add to list.
switch wd.State {
case "idle", "runnable", "running", "syscall",
"waiting", "dead", "enqueue", "copystack":
wi.Running++
case "chan send", "chan receive", "select", "IO wait",
"panicwait", "semacquire", "semarelease", "sleep",
"sync.Mutex.Lock":
wi.Waiting++
case "":
if w.workerMgr != nil {
wi.Waiting++
wd.State = "scheduled"
wd.ExtraInfo = w.workerMgr.Status()
} else {
wi.Missing++
wd.State = "missing"
}
default:
wi.Other++
}
wi.Workers = append(wi.Workers, wd)
}
// Sort and return.
wi.clean()
return wi, nil
}
// Format formats the worker information as a readable table.
func (wi *WorkerInfo) Format() string {
buf := bytes.NewBuffer(nil)
// Add summary.
buf.WriteString(fmt.Sprintf(
"%d Workers: %d running, %d waiting\n\n",
len(wi.Workers),
wi.Running,
wi.Waiting,
))
// Build table.
tabWriter := tabwriter.NewWriter(buf, 4, 4, 3, ' ', 0)
_, _ = fmt.Fprintf(tabWriter, "#\tState\tModule\tName\tWorker Func\tCurrent Line\tExtra Info\n")
for _, wd := range wi.Workers {
_, _ = fmt.Fprintf(tabWriter,
"%d\t%s\t%s\t%s\t%s\t%s\t%s\n",
wd.Count,
wd.State,
wd.Mgr,
wd.Name,
wd.Func,
wd.CurrentLine,
wd.ExtraInfo,
)
}
_ = tabWriter.Flush()
return buf.String()
}
func getFuncName(fn func(w *WorkerCtx) error) string {
name := runtime.FuncForPC(reflect.ValueOf(fn).Pointer()).Name()
return strings.TrimSuffix(name, "-fm")
}
func fullStack() []byte {
buf := make([]byte, 8096)
for {
n := runtime.Stack(buf, true)
if n < len(buf) {
return buf[:n]
}
buf = make([]byte, 2*len(buf))
}
}
// MergeWorkerInfo merges multiple worker infos into one.
func MergeWorkerInfo(infos ...*WorkerInfo) *WorkerInfo {
// Calculate total registered workers.
var totalWorkers int
for _, status := range infos {
totalWorkers += len(status.Workers)
}
// Merge all worker infos.
wi := &WorkerInfo{
Workers: make([]*WorkerInfoDetail, 0, totalWorkers),
}
for _, info := range infos {
wi.Running += info.Running
wi.Waiting += info.Waiting
wi.Other += info.Other
wi.Missing += info.Missing
wi.Workers = append(wi.Workers, info.Workers...)
}
// Sort and return.
wi.clean()
return wi
}
func (wi *WorkerInfo) clean() {
// Check if there is anything to do.
if len(wi.Workers) <= 1 {
return
}
// Sort for deduplication.
slices.SortFunc(wi.Workers, sortWorkerInfoDetail)
// Count duplicate worker details.
current := wi.Workers[0]
for i := 1; i < len(wi.Workers); i++ {
if workerDetailsAreEqual(current, wi.Workers[i]) {
current.Count++
} else {
current = wi.Workers[i]
}
}
// Deduplicate worker details.
wi.Workers = slices.CompactFunc(wi.Workers, workerDetailsAreEqual)
// Sort for presentation.
slices.SortFunc(wi.Workers, sortWorkerInfoDetailByCount)
}
// sortWorkerInfoDetail is a sort function to sort worker info details by their content.
func sortWorkerInfoDetail(a, b *WorkerInfoDetail) int {
switch {
case a.State != b.State:
return strings.Compare(a.State, b.State)
case a.Mgr != b.Mgr:
return strings.Compare(a.Mgr, b.Mgr)
case a.Name != b.Name:
return strings.Compare(a.Name, b.Name)
case a.Func != b.Func:
return strings.Compare(a.Func, b.Func)
case a.CurrentLine != b.CurrentLine:
return strings.Compare(a.CurrentLine, b.CurrentLine)
case a.ExtraInfo != b.ExtraInfo:
return strings.Compare(a.ExtraInfo, b.ExtraInfo)
case a.Count != b.Count:
return b.Count - a.Count
default:
return 0
}
}
// sortWorkerInfoDetailByCount is a sort function to sort worker info details by their count and then by content.
func sortWorkerInfoDetailByCount(a, b *WorkerInfoDetail) int {
stateA, stateB := goroutineStateOrder(a.State), goroutineStateOrder(b.State)
switch {
case stateA != stateB:
return stateA - stateB
case a.State != b.State:
return strings.Compare(a.State, b.State)
case a.Count != b.Count:
return b.Count - a.Count
case a.Mgr != b.Mgr:
return strings.Compare(a.Mgr, b.Mgr)
case a.Name != b.Name:
return strings.Compare(a.Name, b.Name)
case a.Func != b.Func:
return strings.Compare(a.Func, b.Func)
case a.CurrentLine != b.CurrentLine:
return strings.Compare(a.CurrentLine, b.CurrentLine)
case a.ExtraInfo != b.ExtraInfo:
return strings.Compare(a.ExtraInfo, b.ExtraInfo)
default:
return 0
}
}
// workerDetailsAreEqual is a deduplication function for worker details.
func workerDetailsAreEqual(a, b *WorkerInfoDetail) bool {
switch {
case a.State != b.State:
return false
case a.Mgr != b.Mgr:
return false
case a.Name != b.Name:
return false
case a.Func != b.Func:
return false
case a.CurrentLine != b.CurrentLine:
return false
case a.ExtraInfo != b.ExtraInfo:
return false
default:
return true
}
}
//nolint:goconst
func goroutineStateOrder(state string) int {
switch state {
case "runnable", "running", "syscall":
return 0 // Active.
case "idle", "waiting", "dead", "enqueue", "copystack":
return 1 // Active-ish.
case "semacquire", "semarelease", "sleep", "panicwait", "sync.Mutex.Lock":
return 2 // Bad (practice) blocking.
case "chan send", "chan receive", "select":
return 3 // Potentially bad (practice), but normal blocking.
case "IO wait":
return 4 // Normal blocking.
case "scheduled":
return 5 // Not running.
case "missing", "":
return 6 // Warning of undetected workers.
default:
return 9
}
}