module Gitlab # This module provides helper methods which are intregrated with GitLab::ExclusiveLease module ExclusiveLeaseHelpers FailedToObtainLockError = Class.new(StandardError) ## # This helper method blocks a process/thread until the other process cancel the obrainted lease key. # # Note: It's basically discouraged to use this method in the unicorn's thread, # because it holds the connection until all `retries` is consumed. # This could potentially eat up all connection pools. def in_lock(key, ttl: 1.minute, retries: 10, sleep_sec: 0.01.seconds) lease = Gitlab::ExclusiveLease.new(key, timeout: ttl) until uuid = lease.try_obtain # Keep trying until we obtain the lease. To prevent hammering Redis too # much we'll wait for a bit. sleep(sleep_sec) break if (retries -= 1) < 0 end raise FailedToObtainLockError, 'Failed to obtain a lock' unless uuid yield ensure Gitlab::ExclusiveLease.cancel(key, uuid) end end end