JRuby中的Clojure STM

Posted 2021-02-26

require "java"
require "clojure.jar"
include_class "clojure.lang.LockingTransaction"
include_class "clojure.lang.Ref"
 
my_account = Ref.new(1)
 
puts "Initial value #{my_account.deref}"
 
begin
  my_account.set(1000)
rescue java.lang.IllegalStateException
  puts "Reference updated outside a transaction.. Naughty.. :)"
end
 
puts "Value after failed update #{my_account.deref}"
 
Thread.new {LockingTransaction.run_in_transaction(Proc.new { my_account.set 1000 })}
 
Thread.new {LockingTransaction.run_in_transaction(Proc.new { sleep 0.1; my_account.set 21000 })} # Will fail because get commited after first transaction 
 
puts "Value after successful transaction #{my_account.deref}"