From be556ada9b92ed84beb0b615096586e8091b994f Mon Sep 17 00:00:00 2001
From: Svarog <feanorr@gmail.com>
Date: Sun, 2 Feb 2020 18:27:18 +0200
Subject: [PATCH]  [NOD-719] Added defers to unlocks  (#618)

* [NOD-719] Added defers to unlocks

* [NOD-719] Added another defer to another Unlock

* [NOD-719] Added yet another defer to yet another Unlock
---
 blockdag/dag.go            | 4 ++--
 blockdag/thresholdstate.go | 4 ++--
 netsync/manager.go         | 9 +++++----
 3 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/blockdag/dag.go b/blockdag/dag.go
index 9b5a1769f..cf6745316 100644
--- a/blockdag/dag.go
+++ b/blockdag/dag.go
@@ -1713,11 +1713,11 @@ func (dag *BlockDAG) antiPastBetween(lowHash, highHash *daghash.Hash, maxEntries
 // This function is safe for concurrent access.
 func (dag *BlockDAG) AntiPastHashesBetween(lowHash, highHash *daghash.Hash, maxHashes uint64) ([]*daghash.Hash, error) {
 	dag.dagLock.RLock()
+	defer dag.dagLock.RUnlock()
 	hashes, err := dag.antiPastHashesBetween(lowHash, highHash, maxHashes)
 	if err != nil {
 		return nil, err
 	}
-	dag.dagLock.RUnlock()
 	return hashes, nil
 }
 
@@ -1791,11 +1791,11 @@ func (dag *BlockDAG) RUnlock() {
 // This function is safe for concurrent access.
 func (dag *BlockDAG) AntiPastHeadersBetween(lowHash, highHash *daghash.Hash) ([]*wire.BlockHeader, error) {
 	dag.dagLock.RLock()
+	defer dag.dagLock.RUnlock()
 	headers, err := dag.antiPastHeadersBetween(lowHash, highHash, wire.MaxBlockHeadersPerMsg)
 	if err != nil {
 		return nil, err
 	}
-	dag.dagLock.RUnlock()
 	return headers, nil
 }
 
diff --git a/blockdag/thresholdstate.go b/blockdag/thresholdstate.go
index a08a1c9af..0ea99c7af 100644
--- a/blockdag/thresholdstate.go
+++ b/blockdag/thresholdstate.go
@@ -267,8 +267,8 @@ func (dag *BlockDAG) thresholdState(prevNode *blockNode, checker thresholdCondit
 // This function is safe for concurrent access.
 func (dag *BlockDAG) ThresholdState(deploymentID uint32) (ThresholdState, error) {
 	dag.dagLock.Lock()
+	defer dag.dagLock.Unlock()
 	state, err := dag.deploymentState(dag.selectedTip(), deploymentID)
-	dag.dagLock.Unlock()
 
 	return state, err
 }
@@ -279,8 +279,8 @@ func (dag *BlockDAG) ThresholdState(deploymentID uint32) (ThresholdState, error)
 // This function is safe for concurrent access.
 func (dag *BlockDAG) IsDeploymentActive(deploymentID uint32) (bool, error) {
 	dag.dagLock.Lock()
+	defer dag.dagLock.Unlock()
 	state, err := dag.deploymentState(dag.selectedTip(), deploymentID)
-	dag.dagLock.Unlock()
 	if err != nil {
 		return false, err
 	}
diff --git a/netsync/manager.go b/netsync/manager.go
index 5d8d0e602..2f5824752 100644
--- a/netsync/manager.go
+++ b/netsync/manager.go
@@ -6,6 +6,11 @@ package netsync
 
 import (
 	"fmt"
+	"net"
+	"sync"
+	"sync/atomic"
+	"time"
+
 	"github.com/kaspanet/kaspad/blockdag"
 	"github.com/kaspanet/kaspad/dagconfig"
 	"github.com/kaspanet/kaspad/database"
@@ -15,10 +20,6 @@ import (
 	"github.com/kaspanet/kaspad/util/daghash"
 	"github.com/kaspanet/kaspad/wire"
 	"github.com/pkg/errors"
-	"net"
-	"sync"
-	"sync/atomic"
-	"time"
 )
 
 const (