status-go/vendor/github.com/raulk/go-watchdog/notification.go

81 lines
1.9 KiB
Go

package watchdog
import "sync"
var (
gcNotifeeMutex sync.Mutex
gcNotifees []notifeeEntry
forcedGCNotifeeMutex sync.Mutex
forcedGCNotifees []notifeeEntry
)
// RegisterPostGCNotifee registers a function that is called every time a GC has happened,
// both GC runs triggered by the Go runtime and by watchdog.
// The unregister function returned can be used to unregister this notifee.
func RegisterPostGCNotifee(f func()) (unregister func()) {
gcNotifeeMutex.Lock()
defer gcNotifeeMutex.Unlock()
var id int
if len(gcNotifees) > 0 {
id = gcNotifees[len(gcNotifees)-1].id + 1
}
gcNotifees = append(gcNotifees, notifeeEntry{id: id, f: f})
return func() {
gcNotifeeMutex.Lock()
defer gcNotifeeMutex.Unlock()
for i, entry := range gcNotifees {
if entry.id == id {
gcNotifees = append(gcNotifees[:i], gcNotifees[i+1:]...)
}
}
}
}
func notifyGC() {
if NotifyGC != nil {
NotifyGC()
}
gcNotifeeMutex.Lock()
defer gcNotifeeMutex.Unlock()
for _, entry := range gcNotifees {
entry.f()
}
}
// RegisterPreGCNotifee registers a function that is called before watchdog triggers a GC run.
// It is ONLY called when watchdog triggers a GC run, not when the Go runtime triggers it.
// The unregister function returned can be used to unregister this notifee.
func RegisterPreGCNotifee(f func()) (unregister func()) {
forcedGCNotifeeMutex.Lock()
defer forcedGCNotifeeMutex.Unlock()
var id int
if len(forcedGCNotifees) > 0 {
id = forcedGCNotifees[len(forcedGCNotifees)-1].id + 1
}
forcedGCNotifees = append(forcedGCNotifees, notifeeEntry{id: id, f: f})
return func() {
forcedGCNotifeeMutex.Lock()
defer forcedGCNotifeeMutex.Unlock()
for i, entry := range forcedGCNotifees {
if entry.id == id {
forcedGCNotifees = append(forcedGCNotifees[:i], forcedGCNotifees[i+1:]...)
}
}
}
}
func notifyForcedGC() {
forcedGCNotifeeMutex.Lock()
defer forcedGCNotifeeMutex.Unlock()
for _, entry := range forcedGCNotifees {
entry.f()
}
}