Fix oom draft flood

Author: nekohasekai

service/oomkiller/service.go

@@ -32,6 +32,8 @@ type Service struct {
 	adaptiveTimer  *adaptiveTimer
 	lastReportTime atomic.Int64
 	//nolint:unused // touched only on darwin && cgo via writeOOMDraft/discardOOMDraft.
+	lastDraftTime atomic.Int64
+	//nolint:unused // touched only on darwin && cgo via writeOOMDraft/discardOOMDraft.
 	draftCancelled atomic.Bool
 }
 

service/oomkiller/service_darwin.go

@@ -34,13 +34,16 @@ import "C"
 
 import (
 	"sync"
+	"time"
 
 	"github.com/sagernet/sing-box/adapter"
 	"github.com/sagernet/sing/common/byteformats"
 	E "github.com/sagernet/sing/common/exceptions"
 	"github.com/sagernet/sing/service"
 )
 
+const oomDraftMinInterval = time.Hour
+
 var (
 	globalAccess   sync.Mutex
 	globalServices []*Service
@@ -109,6 +112,14 @@ func (s *Service) writeOOMDraft(memoryUsage uint64) {
 	if s.draftCancelled.Load() {
 		return
 	}
+	now := time.Now().UnixNano()
+	lastDraft := s.lastDraftTime.Load()
+	if time.Duration(now-lastDraft) < oomDraftMinInterval {
+		return
+	}
+	if !s.lastDraftTime.CompareAndSwap(lastDraft, now) {
+		return
+	}
 	reporter := service.FromContext[OOMReporter](s.ctx)
 	if reporter == nil {
 		return