mirror of
https://github.com/ceph/ceph-csi.git
synced 2024-12-24 22:10:23 +00:00
174 lines
5.0 KiB
Go
174 lines
5.0 KiB
Go
/*
|
|
Copyright 2014 The Kubernetes Authors.
|
|
|
|
Licensed under the Apache License, Version 2.0 (the "License");
|
|
you may not use this file except in compliance with the License.
|
|
You may obtain a copy of the License at
|
|
|
|
http://www.apache.org/licenses/LICENSE-2.0
|
|
|
|
Unless required by applicable law or agreed to in writing, software
|
|
distributed under the License is distributed on an "AS IS" BASIS,
|
|
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
See the License for the specific language governing permissions and
|
|
limitations under the License.
|
|
*/
|
|
|
|
package runtime
|
|
|
|
import (
|
|
"fmt"
|
|
"runtime"
|
|
"sync"
|
|
"time"
|
|
|
|
"k8s.io/klog"
|
|
)
|
|
|
|
var (
|
|
// ReallyCrash controls the behavior of HandleCrash and now defaults
|
|
// true. It's still exposed so components can optionally set to false
|
|
// to restore prior behavior.
|
|
ReallyCrash = true
|
|
)
|
|
|
|
// PanicHandlers is a list of functions which will be invoked when a panic happens.
|
|
var PanicHandlers = []func(interface{}){logPanic}
|
|
|
|
// HandleCrash simply catches a crash and logs an error. Meant to be called via
|
|
// defer. Additional context-specific handlers can be provided, and will be
|
|
// called in case of panic. HandleCrash actually crashes, after calling the
|
|
// handlers and logging the panic message.
|
|
//
|
|
// TODO: remove this function. We are switching to a world where it's safe for
|
|
// apiserver to panic, since it will be restarted by kubelet. At the beginning
|
|
// of the Kubernetes project, nothing was going to restart apiserver and so
|
|
// catching panics was important. But it's actually much simpler for monitoring
|
|
// software if we just exit when an unexpected panic happens.
|
|
func HandleCrash(additionalHandlers ...func(interface{})) {
|
|
if r := recover(); r != nil {
|
|
for _, fn := range PanicHandlers {
|
|
fn(r)
|
|
}
|
|
for _, fn := range additionalHandlers {
|
|
fn(r)
|
|
}
|
|
if ReallyCrash {
|
|
// Actually proceed to panic.
|
|
panic(r)
|
|
}
|
|
}
|
|
}
|
|
|
|
// logPanic logs the caller tree when a panic occurs.
|
|
func logPanic(r interface{}) {
|
|
callers := getCallers(r)
|
|
if _, ok := r.(string); ok {
|
|
klog.Errorf("Observed a panic: %s\n%v", r, callers)
|
|
} else {
|
|
klog.Errorf("Observed a panic: %#v (%v)\n%v", r, r, callers)
|
|
}
|
|
}
|
|
|
|
func getCallers(r interface{}) string {
|
|
callers := ""
|
|
for i := 0; true; i++ {
|
|
_, file, line, ok := runtime.Caller(i)
|
|
if !ok {
|
|
break
|
|
}
|
|
callers = callers + fmt.Sprintf("%v:%v\n", file, line)
|
|
}
|
|
|
|
return callers
|
|
}
|
|
|
|
// ErrorHandlers is a list of functions which will be invoked when an unreturnable
|
|
// error occurs.
|
|
// TODO(lavalamp): for testability, this and the below HandleError function
|
|
// should be packaged up into a testable and reusable object.
|
|
var ErrorHandlers = []func(error){
|
|
logError,
|
|
(&rudimentaryErrorBackoff{
|
|
lastErrorTime: time.Now(),
|
|
// 1ms was the number folks were able to stomach as a global rate limit.
|
|
// If you need to log errors more than 1000 times a second you
|
|
// should probably consider fixing your code instead. :)
|
|
minPeriod: time.Millisecond,
|
|
}).OnError,
|
|
}
|
|
|
|
// HandlerError is a method to invoke when a non-user facing piece of code cannot
|
|
// return an error and needs to indicate it has been ignored. Invoking this method
|
|
// is preferable to logging the error - the default behavior is to log but the
|
|
// errors may be sent to a remote server for analysis.
|
|
func HandleError(err error) {
|
|
// this is sometimes called with a nil error. We probably shouldn't fail and should do nothing instead
|
|
if err == nil {
|
|
return
|
|
}
|
|
|
|
for _, fn := range ErrorHandlers {
|
|
fn(err)
|
|
}
|
|
}
|
|
|
|
// logError prints an error with the call stack of the location it was reported
|
|
func logError(err error) {
|
|
klog.ErrorDepth(2, err)
|
|
}
|
|
|
|
type rudimentaryErrorBackoff struct {
|
|
minPeriod time.Duration // immutable
|
|
// TODO(lavalamp): use the clock for testability. Need to move that
|
|
// package for that to be accessible here.
|
|
lastErrorTimeLock sync.Mutex
|
|
lastErrorTime time.Time
|
|
}
|
|
|
|
// OnError will block if it is called more often than the embedded period time.
|
|
// This will prevent overly tight hot error loops.
|
|
func (r *rudimentaryErrorBackoff) OnError(error) {
|
|
r.lastErrorTimeLock.Lock()
|
|
defer r.lastErrorTimeLock.Unlock()
|
|
d := time.Since(r.lastErrorTime)
|
|
if d < r.minPeriod {
|
|
// If the time moves backwards for any reason, do nothing
|
|
time.Sleep(r.minPeriod - d)
|
|
}
|
|
r.lastErrorTime = time.Now()
|
|
}
|
|
|
|
// GetCaller returns the caller of the function that calls it.
|
|
func GetCaller() string {
|
|
var pc [1]uintptr
|
|
runtime.Callers(3, pc[:])
|
|
f := runtime.FuncForPC(pc[0])
|
|
if f == nil {
|
|
return fmt.Sprintf("Unable to find caller")
|
|
}
|
|
return f.Name()
|
|
}
|
|
|
|
// RecoverFromPanic replaces the specified error with an error containing the
|
|
// original error, and the call tree when a panic occurs. This enables error
|
|
// handlers to handle errors and panics the same way.
|
|
func RecoverFromPanic(err *error) {
|
|
if r := recover(); r != nil {
|
|
callers := getCallers(r)
|
|
|
|
*err = fmt.Errorf(
|
|
"recovered from panic %q. (err=%v) Call stack:\n%v",
|
|
r,
|
|
*err,
|
|
callers)
|
|
}
|
|
}
|
|
|
|
// Must panics on non-nil errors. Useful to handling programmer level errors.
|
|
func Must(err error) {
|
|
if err != nil {
|
|
panic(err)
|
|
}
|
|
}
|