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package cluster
import ( "context" "fmt" "github.com/seaweedfs/seaweedfs/weed/cluster/lock_manager" "github.com/seaweedfs/seaweedfs/weed/glog" "github.com/seaweedfs/seaweedfs/weed/pb" "github.com/seaweedfs/seaweedfs/weed/pb/filer_pb" "github.com/seaweedfs/seaweedfs/weed/util" "google.golang.org/grpc" "time" )
type LockClient struct { grpcDialOption grpc.DialOption maxLockDuration time.Duration sleepDuration time.Duration seedFiler pb.ServerAddress }
func NewLockClient(grpcDialOption grpc.DialOption, seedFiler pb.ServerAddress) *LockClient { return &LockClient{ grpcDialOption: grpcDialOption, maxLockDuration: 5 * time.Second, sleepDuration: 2473 * time.Millisecond, seedFiler: seedFiler, } }
type LiveLock struct { key string renewToken string expireAtNs int64 filer pb.ServerAddress cancelCh chan struct{} grpcDialOption grpc.DialOption isLocked bool owner string lc *LockClient }
// NewLock creates a lock with a very long duration
func (lc *LockClient) NewLock(key string, owner string) (lock *LiveLock) { return lc.doNewLock(key, lock_manager.MaxDuration, owner) }
// StartLock starts a goroutine to lock the key and returns immediately.
func (lc *LockClient) StartLock(key string, owner string) (lock *LiveLock) { lock = &LiveLock{ key: key, filer: lc.seedFiler, cancelCh: make(chan struct{}), expireAtNs: time.Now().Add(lock_manager.MaxDuration).UnixNano(), grpcDialOption: lc.grpcDialOption, owner: owner, lc: lc, } go func() { util.RetryForever("create lock:"+key, func() error { errorMessage, err := lock.doLock(lock_manager.MaxDuration) if err != nil { glog.Infof("create lock %s: %s", key, err) time.Sleep(time.Second) return err } if errorMessage != "" { glog.Infof("create lock %s: %s", key, errorMessage) time.Sleep(time.Second) return fmt.Errorf("%v", errorMessage) } lock.isLocked = true return nil }, func(err error) (shouldContinue bool) { if err != nil { glog.Warningf("create lock %s: %s", key, err) time.Sleep(time.Second) } return lock.renewToken == "" }) lc.keepLock(lock) }() return }
func (lc *LockClient) doNewLock(key string, lockDuration time.Duration, owner string) (lock *LiveLock) { lock = &LiveLock{ key: key, filer: lc.seedFiler, cancelCh: make(chan struct{}), expireAtNs: time.Now().Add(lockDuration).UnixNano(), grpcDialOption: lc.grpcDialOption, owner: owner, lc: lc, } var needRenewal bool if lockDuration > lc.maxLockDuration { lockDuration = lc.maxLockDuration needRenewal = true } util.RetryForever("create lock:"+key, func() error { errorMessage, err := lock.doLock(lockDuration) if err != nil { time.Sleep(time.Second) return err } if errorMessage != "" { time.Sleep(time.Second) return fmt.Errorf("%v", errorMessage) } lock.isLocked = true return nil }, func(err error) (shouldContinue bool) { if err != nil { glog.Warningf("create lock %s: %s", key, err) } return lock.renewToken == "" })
if needRenewal { go lc.keepLock(lock) }
return }
func (lock *LiveLock) IsLocked() bool { return lock.isLocked }
func (lock *LiveLock) StopLock() error { close(lock.cancelCh) if !lock.isLocked { return nil } return pb.WithFilerClient(false, 0, lock.filer, lock.grpcDialOption, func(client filer_pb.SeaweedFilerClient) error { _, err := client.DistributedUnlock(context.Background(), &filer_pb.UnlockRequest{ Name: lock.key, RenewToken: lock.renewToken, }) return err }) }
func (lc *LockClient) keepLock(lock *LiveLock) { ticker := time.Tick(lc.sleepDuration) for { select { case <-ticker: // renew the lock if lock.expireAtNs is still greater than now
util.RetryForever("keep lock:"+lock.key, func() error { lockDuration := time.Duration(lock.expireAtNs-time.Now().UnixNano()) * time.Nanosecond if lockDuration > lc.maxLockDuration { lockDuration = lc.maxLockDuration } if lockDuration <= 0 { return nil }
errorMessage, err := lock.doLock(lockDuration) if err != nil { lock.isLocked = false time.Sleep(time.Second) return err } if errorMessage != "" { lock.isLocked = false time.Sleep(time.Second) return fmt.Errorf("%v", errorMessage) } return nil }, func(err error) (shouldContinue bool) { if err == nil { return false } glog.Warningf("keep lock %s: %v", lock.key, err) return true }) if !lock.isLocked { return } case <-lock.cancelCh: return } } }
func (lock *LiveLock) doLock(lockDuration time.Duration) (errorMessage string, err error) { err = pb.WithFilerClient(false, 0, lock.filer, lock.grpcDialOption, func(client filer_pb.SeaweedFilerClient) error { resp, err := client.DistributedLock(context.Background(), &filer_pb.LockRequest{ Name: lock.key, SecondsToLock: int64(lockDuration.Seconds()), RenewToken: lock.renewToken, IsMoved: false, Owner: lock.owner, }) if err == nil { lock.renewToken = resp.RenewToken } if resp != nil { errorMessage = resp.Error if resp.MovedTo != "" { lock.filer = pb.ServerAddress(resp.MovedTo) lock.lc.seedFiler = lock.filer } } return err }) return }
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