From 2fa40642a9ab4bbbafc52f6d43473163d47fbf1a Mon Sep 17 00:00:00 2001
From: mappu <mappu04@gmail.com>
Date: Wed, 22 Nov 2017 20:07:26 +1300
Subject: [PATCH] switch to "hat" pattern for mutexes

--HG--
branch : adc
---
 HubConnection.go | 27 ++++++++++++++-------------
 NmdcProtocol.go  | 12 ++++++------
 2 files changed, 20 insertions(+), 19 deletions(-)

diff --git a/HubConnection.go b/HubConnection.go
index cec8d47..7cb9c4f 100644
--- a/HubConnection.go
+++ b/HubConnection.go
@@ -14,10 +14,11 @@ type HubConnection struct {
 	Hco *HubConnectionOptions
 
 	// Current remote status
-	HubName  string
-	State    ConnectionState
+	HubName string
+	State   ConnectionState
+
+	usersMut sync.RWMutex
 	users    map[string]UserInfo
-	userLock sync.RWMutex
 
 	proto Protocol
 
@@ -33,8 +34,8 @@ type HubConnection struct {
 
 // Thread-safe user accessor.
 func (this *HubConnection) Users(cb func(*map[string]UserInfo) error) error {
-	this.userLock.Lock()
-	defer this.userLock.Unlock()
+	this.usersMut.Lock()
+	defer this.usersMut.Unlock()
 
 	return cb(&this.users)
 }
@@ -48,16 +49,16 @@ func (this *HubConnection) SayPrivate(recipient string, message string) {
 }
 
 func (this *HubConnection) UserExists(nick string) bool {
-	this.userLock.RLock()
-	defer this.userLock.RUnlock()
+	this.usersMut.RLock()
+	defer this.usersMut.RUnlock()
 
 	_, already_existed := this.users[nick]
 	return already_existed
 }
 
 func (this *HubConnection) UserCount() int {
-	this.userLock.RLock()
-	defer this.userLock.RUnlock()
+	this.usersMut.RLock()
+	defer this.usersMut.RUnlock()
 
 	return len(this.users)
 }
@@ -65,9 +66,9 @@ func (this *HubConnection) UserCount() int {
 func (this *HubConnection) userJoined_NameOnly(nick string) {
 	if !this.UserExists(nick) {
 
-		this.userLock.Lock()
+		this.usersMut.Lock()
 		this.users[nick] = *NewUserInfo(nick)
-		this.userLock.Unlock() // Don't lock over a processEvent boundary
+		this.usersMut.Unlock() // Don't lock over a processEvent boundary
 
 		this.processEvent(HubEvent{EventType: EVENT_USER_JOINED, Nick: nick})
 	}
@@ -75,10 +76,10 @@ func (this *HubConnection) userJoined_NameOnly(nick string) {
 
 func (this *HubConnection) userJoined_Full(uinf *UserInfo) {
 	// n.b. also called when we get a replacement MyINFO for someone
-	this.userLock.Lock()
+	this.usersMut.Lock()
 	_, userExisted := this.users[uinf.Nick] // don't use UserExists as it would deadlock the mutex
 	this.users[uinf.Nick] = *uinf
-	this.userLock.Unlock() // Don't lock over a processEvent boundary
+	this.usersMut.Unlock() // Don't lock over a processEvent boundary
 
 	if !userExisted {
 		this.processEvent(HubEvent{EventType: EVENT_USER_JOINED, Nick: uinf.Nick})
diff --git a/NmdcProtocol.go b/NmdcProtocol.go
index db209fe..42dce25 100644
--- a/NmdcProtocol.go
+++ b/NmdcProtocol.go
@@ -117,9 +117,9 @@ func (this *NmdcProtocol) ProcessCommand(message string) {
 		}
 
 	case "$Quit":
-		this.hc.userLock.Lock()
+		this.hc.usersMut.Lock()
 		delete(this.hc.users, commandParts[1])
-		this.hc.userLock.Unlock() // Don't lock over a processEvent boundary
+		this.hc.usersMut.Unlock() // Don't lock over a processEvent boundary
 
 		this.hc.processEvent(HubEvent{EventType: EVENT_USER_PART, Nick: commandParts[1]})
 
@@ -156,8 +156,8 @@ func (this *NmdcProtocol) ProcessCommand(message string) {
 		// Mark all mentioned nicks as being operators, and all unmentioned nicks
 		//  as being /not/ an operator. (second pass minimises RW mutex use)
 		func() {
-			this.hc.userLock.Lock()
-			defer this.hc.userLock.Unlock()
+			this.hc.usersMut.Lock()
+			defer this.hc.usersMut.Unlock()
 
 			for nick, userinfo := range this.hc.users {
 				_, isop := opmap[nick]
@@ -182,7 +182,7 @@ func (this *NmdcProtocol) ProcessCommand(message string) {
 		}
 
 	case "$UserIP":
-		this.hc.userLock.Lock()
+		this.hc.usersMut.Lock()
 
 		pairs := strings.Split(commandParts[1], "$$")
 		notifyOfUpdate := make([]string, 0, len(pairs))
@@ -211,7 +211,7 @@ func (this *NmdcProtocol) ProcessCommand(message string) {
 			}
 		}
 
-		this.hc.userLock.Unlock()
+		this.hc.usersMut.Unlock()
 
 		for _, nick := range notifyOfUpdate {
 			this.hc.processEvent(HubEvent{EventType: EVENT_USER_UPDATED_INFO, Nick: nick})