@startuml serialized

!pragma teoz true
hide footbox

participant Alice 
participant Server 
participant Bob 


Alice ->(10) Server : lock()
Server -->(10) Alice : true

Bob -> Server : lock()
& Alice ->(10) Server : inserer("hello world")
Server -->(10) Bob : false
& Alice ->(10) Server : lire()
Server -->(10) Alice : "hello world"
Alice -> Server : unlock()
Bob -> Server : lock()
Bob -> Server : lire()
Server -->(10) Bob : "hello world"
Bob -> Server : unlock()

@enduml