miner, wemix: work logging before registering mined block

miner/worker.go

@@ -1758,6 +1758,11 @@ func (w *worker) commitEx(env *environment, interval func(), update bool, start
 					}
 					logs = append(logs, receipt.Logs...)
 				}
+				if !wemixminer.IsPoW() {
+					if err = wemixminer.ReleaseMiningToken(sealedBlock.Number(), sealedBlock.Hash(), sealedBlock.ParentHash()); err != nil {
+						return err
+					}
+				}
 				// Commit block and state to database.
 				_, err := w.chain.WriteBlockAndSetHead(sealedBlock, receipts, logs, env.state, true)
 				if err != nil {
@@ -1767,12 +1772,6 @@ func (w *worker) commitEx(env *environment, interval func(), update bool, start
 				log.Info("Successfully sealed new block", "number", sealedBlock.Number(), "sealhash", sealhash, "hash", hash,
 					"elapsed", common.PrettyDuration(time.Since(createdAt)))
 
-				if !wemixminer.IsPoW() {
-					if err = wemixminer.ReleaseMiningToken(sealedBlock.Number(), sealedBlock.Hash(), sealedBlock.ParentHash()); err != nil {
-						return err
-					}
-				}
-
 				// Broadcast the block and announce chain insertion event
 				w.mux.Post(core.NewMinedBlockEvent{Block: sealedBlock})
 

wemix/sync.go

@@ -169,10 +169,17 @@ func releaseMiningToken(height *big.Int, hash, parentHash common.Hash) error {
 	if lck == nil || lck.ttl() < 0 {
 		return wemixminer.ErrNotInitialized
 	}
-	ctx, cancel := context.WithTimeout(context.Background(),
-		admin.etcd.Server.Cfg.ReqTimeout())
-	defer cancel()
-	err := lck.releaseTokenSync(ctx, height, hash, parentHash)
+	var err error
+	for range []int{1, 2} {
+		// retry in case it fails to release due to leader changes, etc.
+		ctx, cancel := context.WithTimeout(context.Background(),
+			admin.etcd.Server.Cfg.ReqTimeout())
+		err = lck.releaseTokenSync(ctx, height, hash, parentHash)
+		cancel()
+		if err == nil {
+			break
+		}
+	}
 
 	// invalidate the saved token
 	miningToken.Store(&WemixToken{})