Deadlock issue

[henrymkw]

This happened when multiple clients logged out/shutdown simultaneously.

Log:

POTENTIAL DEADLOCK: Inconsistent locking. saw this ordering in one goroutine:
happened before
gpcm/friend.go:92 gpcm.(*GameSpySession).addFriend { mutex.Lock() } <<<<<
~/go/pkg/mod/github.com/sasha-s/go-deadlock@v0.3.5/deadlock.go:87 go-deadlock.(*Mutex).Lock { func (m *Mutex) Lock() { }
gpcm/main.go:282 gpcm.(*GameSpySession).handleCommand {  }
gpcm/main.go:249 gpcm.HandlePacket { commands = session.handleCommand("status", commands, session.setStatus) }
main.go:182 main.(*RPCPacket).HandlePacket { case "gpcm": }
/usr/lib/golang/src/reflect/value.go:583 reflect.Value.call { // For testing; see TestCallMethodJump. }
/usr/lib/golang/src/reflect/value.go:364 reflect.Value.Call { v.mustBeExported() }
/usr/lib/golang/src/net/rpc/server.go:384 rpc.(*service).call { // The return value for the method is an error. }

happened after
qr2/logins.go:124 qr2.AddToFriendsList { mutex.Lock() } <<<<<
~/go/pkg/mod/github.com/sasha-s/go-deadlock@v0.3.5/deadlock.go:87 go-deadlock.(*Mutex).Lock { func (m *Mutex) Lock() { }
gpcm/friend.go:110 gpcm.(*GameSpySession).addFriend { // Check if destination has added the sender }
gpcm/main.go:282 gpcm.(*GameSpySession).handleCommand {  }
gpcm/main.go:249 gpcm.HandlePacket { commands = session.handleCommand("status", commands, session.setStatus) }
main.go:182 main.(*RPCPacket).HandlePacket { case "gpcm": }
/usr/lib/golang/src/reflect/value.go:583 reflect.Value.call { // For testing; see TestCallMethodJump. }
/usr/lib/golang/src/reflect/value.go:364 reflect.Value.Call { v.mustBeExported() }
/usr/lib/golang/src/net/rpc/server.go:384 rpc.(*service).call { // The return value for the method is an error. }

in another goroutine: happened before
qr2/heartbeat.go:73 qr2.heartbeat { mutex.Lock() } <<<<<
~/go/pkg/mod/github.com/sasha-s/go-deadlock@v0.3.5/deadlock.go:87 go-deadlock.(*Mutex).Lock { func (m *Mutex) Lock() { }
qr2/main.go:200 qr2.handleConnection { // logging.Info(moduleName, "Command:", aurora.Yellow("HEARTBEAT")) }

happened after
gpcm/main.go:115 gpcm.CloseConnection { mutex.Lock() } <<<<<
~/go/pkg/mod/github.com/sasha-s/go-deadlock@v0.3.5/deadlock.go:87 go-deadlock.(*Mutex).Lock { func (m *Mutex) Lock() { }
main.go:198 main.(*RPCPacket).CloseConnection { case "gpcm": }
/usr/lib/golang/src/reflect/value.go:583 reflect.Value.call { // For testing; see TestCallMethodJump. }
/usr/lib/golang/src/reflect/value.go:364 reflect.Value.Call { v.mustBeExported() }
/usr/lib/golang/src/net/rpc/server.go:384 rpc.(*service).call { // The return value for the method is an error. }

Other goroutines holding locks:
goroutine 824638926784 lock 0xf09398
qr2/heartbeat.go:73 qr2.heartbeat { mutex.Lock() } <<<<<
~/go/pkg/mod/github.com/sasha-s/go-deadlock@v0.3.5/deadlock.go:87 go-deadlock.(*Mutex).Lock { func (m *Mutex) Lock() { }
qr2/main.go:200 qr2.handleConnection { // logging.Info(moduleName, "Command:", aurora.Yellow("HEARTBEAT")) }



2026/06/06 06:55:02 E[FRONTEND]: Failed to forward close connection to backend: unexpected EOF
2026/06/06 06:55:03 E[FRONTEND]: Failed to forward close connection to backend: connection is shut down