我想動態(tài)加載配置文件，而不是重新啟動我的Go應用程序。我寫了下面的文件，這些文件可以運行，但有數(shù)據(jù)競爭。配置.gopackage mainimport ( "github.com/fsnotify/fsnotify" "github.com/spf13/viper" "log" "sync" "time")var ( reloadConfig = make(chan string) reloadConfig2 = make(chan string) viperLock1 sync.Mutex viperLock2 sync.Mutex)func setUpConfig(file string, merge bool, v *viper.Viper) { v.AddConfigPath("./") v.SetConfigName(file) v.SetConfigType("yml") if merge { err1 := v.MergeInConfig() checkForFatalError("fatal error occurred while reading config file!", err1) } else { err := v.ReadInConfig() checkForFatalError("fatal error occurred while reading config file!", err) } log.Println("Initial config value: ", v.GetString("env"))}func loadConfigDynamically(configChannel chan string, viperLock *sync.Mutex, vipe *viper.Viper) { viperLock.Lock() vipe.OnConfigChange(func(e fsnotify.Event) { viperLock.Lock() log.Println("config file changed", e.Name) environment := vipe.GetString("env") configChannel <- environment viperLock.Unlock() }) viperLock.Unlock() vipe.WatchConfig()}func loadMultipleConfigsDynamically() { go func() { time.Sleep(time.Millisecond * 50) vipe2 := viper.New() setUpConfig("config_base", false, vipe2) loadConfigDynamically(reloadConfig2, &viperLock2, vipe2) time.Sleep(time.Millisecond * 50) vipe1 := viper.New() setUpConfig("config", false, vipe1) loadConfigDynamically(reloadConfig, &viperLock1, vipe1) }()}主要.gopackage mainimport ( log "github.com/sirupsen/logrus" "os" "os/signal" "syscall")var reloadConfigNow = make(chan bool)var reloadConfigAgain = make(chan bool)var newConfigValue stringfunc main() { loadMultipleConfigsDynamically() go printUpdatedValueOnly() go justAnotherGoroutine() go yetAnotherGoroutine() shutdownAppGracefully()}
2 回答
瀟湘沐
TA貢獻1816條經(jīng)驗 獲得超6個贊
您鎖定調(diào)用并設置了一個功能，它也鎖定了。viperLockvipe.WatchConfig()vipe.OnConfigChangeviperLock
因為你已經(jīng)打過電話，然后它開始打電話給單獨的go例程。它也試圖獲取相同的鎖。這就是存在爭用條件的原因。vipe.WatchConfig()vipe.OnConfigChange
在設置后和釋放鎖后調(diào)用。vipe.WatchConfig()vipe.OnConfigChange
應按如下方式更正。
func loadConfigDynamically() {
go func() {
time.Sleep(time.Second)
viperLock.Lock()
vipe.OnConfigChange(func(e fsnotify.Event) {
viperLock.Lock()
log.Println("config file changed", e.Name)
environment := vipe.GetString("env")
reloadConfig <- environment
viperLock.Unlock()
})
viperLock.Unlock()
vipe.WatchConfig() //this starting call vipe.OnConfigChange
}()
}
牧羊人nacy
TA貢獻1862條經(jīng)驗 獲得超7個贊
可能是 go 認為變量正在同時被兩個 goroutine 修改和訪問，并且修改和訪問的位置沒有鎖定。類似于以下示例：
package main
import (
"time"
)
type Foo struct {
f func(string)
}
func (f *Foo) Watch() {
go func() {
for {
time.Sleep(time.Second * 2)
if f.f != nil {
f.f("hello world")
}
}
}()
}
func (f *Foo) SetF(fun func(string)) {
f.f = fun
}
func main() {
f := Foo{}
f.Watch()
f.SetF(func(s string) {
})
time.Sleep(time.Second * 5)
}
它有一場數(shù)據(jù)競賽。如果我在修改和讀取的地方都放了相同的鎖，就不會有數(shù)據(jù)競爭：
package main
import (
"sync"
"time"
)
var lock sync.Mutex
type Foo struct {
f func(string)
}
func (f *Foo) Watch() {
go func() {
for {
time.Sleep(time.Second * 2)
lock.Lock() // read places
if f.f != nil {
f.f("hello world")
}
lock.Unlock()
}
}()
}
func (f *Foo) SetF(fun func(string)) {
f.f = fun
}
func main() {
f := Foo{}
f.Watch()
lock.Lock() // write places
f.SetF(func(s string) {
})
lock.Unlock()
time.Sleep(time.Second * 5)
}
或者消除兩個哥律同時閱讀和寫入的可能性會很好：
func main() {
f := Foo{}
f.SetF(func(s string) {
})
f.Watch()
time.Sleep(time.Second * 5)
}
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