class Sidecloq::Locker
Locker
obtains or waits for an exclusive lock on a key in redis
Constants
- DEFAULT_LOCK_KEY
Public Class Methods
new(options = {})
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# File lib/sidecloq/locker.rb, line 8 def initialize(options = {}) # we keep a connection from the pool by default @redis = options[:redis] || Sidekiq.redis_pool.checkout @key = options[:lock_key] || DEFAULT_LOCK_KEY @ttl = options[:ttl] || 60 @check_interval = options[:check_interval] || 15 @lock_manager = Redlock::Client.new([@redis]) @obtained_lock = Concurrent::Event.new @check_task = nil @lock = nil @stopping = false @in_with_lock = false end
Public Instance Methods
locked?()
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# File lib/sidecloq/locker.rb, line 55 def locked? !@stopping && @lock && @obtained_lock.set? end
stop(timeout = nil)
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# File lib/sidecloq/locker.rb, line 37 def stop(timeout = nil) return if @stopping @stopping = true if @check_task logger.debug('Stopping locker check task') @check_task.shutdown @check_task.wait_for_termination(timeout) logger.debug('Stopped locker check task') end # release the lock in case someone is blocked on with_lock @obtained_lock.set @stopping = false unless @in_with_lock end
with_lock() { || ... }
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blocks until lock is obtained, then yields
# File lib/sidecloq/locker.rb, line 23 def with_lock @in_with_lock = true start @obtained_lock.wait yield if locked? stop @stopping = false @in_with_lock = false end
Private Instance Methods
start()
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# File lib/sidecloq/locker.rb, line 61 def start logger.debug('Starting locker check task') @check_task = Concurrent::TimerTask.new( execution_interval: @check_interval, run_now: true ) do try_to_get_or_refresh_lock end @check_task.execute # return the check task, to help with tests @check_task end
try_to_get_or_refresh_lock()
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# File lib/sidecloq/locker.rb, line 75 def try_to_get_or_refresh_lock # redlock is in ms, not seconds if @lock @lock = @lock_manager.lock(@key, @ttl * 1000, extend: @lock) else @lock = @lock_manager.lock(@key, @ttl * 1000) end @obtained_lock.set if @lock logger.debug("Leader lock #{'not ' unless @lock}held") @lock end