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more fine-grained locking around user map (fixes deadlock if callee uses Users() in response to processEvent)

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This commit is contained in:
mappu 2017-02-05 19:06:17 +13:00
parent 7f898dff32
commit 3cc31323ad
1 changed files with 7 additions and 10 deletions
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17
HubConnection.go
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@ -67,10 +67,11 @@ func (this *HubConnection) UserCount() int {
func (this *HubConnection) userJoined_NameOnly(nick string) { func (this *HubConnection) userJoined_NameOnly(nick string) {
if !this.UserExists(nick) { if !this.UserExists(nick) {
this.userLock.Lock()
defer this.userLock.Unlock()
this.userLock.Lock()
this.users[nick] = *NewUserInfo(nick) this.users[nick] = *NewUserInfo(nick)
this.userLock.Unlock() // Don't lock over a processEvent boundary
this.processEvent(HubEvent{EventType: EVENT_USER_JOINED, Nick: nick}) this.processEvent(HubEvent{EventType: EVENT_USER_JOINED, Nick: nick})
} }
} }
@ -78,11 +79,9 @@ func (this *HubConnection) userJoined_NameOnly(nick string) {
func (this *HubConnection) userJoined_Full(uinf *UserInfo) { func (this *HubConnection) userJoined_Full(uinf *UserInfo) {
// n.b. also called when we get a replacement MyINFO for someone // n.b. also called when we get a replacement MyINFO for someone
this.userLock.Lock() this.userLock.Lock()
defer this.userLock.Unlock()
_, userExisted := this.users[uinf.Nick] // don't use UserExists as it would deadlock the mutex _, userExisted := this.users[uinf.Nick] // don't use UserExists as it would deadlock the mutex
this.users[uinf.Nick] = *uinf this.users[uinf.Nick] = *uinf
this.userLock.Unlock() // Don't lock over a processEvent boundary
if !userExisted { if !userExisted {
this.processEvent(HubEvent{EventType: EVENT_USER_JOINED, Nick: uinf.Nick}) this.processEvent(HubEvent{EventType: EVENT_USER_JOINED, Nick: uinf.Nick})
@ -177,12 +176,10 @@ func (this *HubConnection) processProtocolMessage(message string) {
} }
case "$Quit": case "$Quit":
func() { this.userLock.Lock()
this.userLock.Lock() delete(this.users, commandParts[1])
defer this.userLock.Unlock() this.userLock.Unlock() // Don't lock over a processEvent boundary
delete(this.users, commandParts[1])
}()
this.processEvent(HubEvent{EventType: EVENT_USER_PART, Nick: commandParts[1]}) this.processEvent(HubEvent{EventType: EVENT_USER_PART, Nick: commandParts[1]})
case "$MyINFO": case "$MyINFO":