Class: RCron

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/rcron/task.rb,
lib/rcron/alarm.rb,
lib/rcron/parser.rb,
lib/rcron/timeout.rb,
lib/rcron/version.rb,
lib/rcron/scheduler.rb

Defined Under Namespace

Modules: Parser Classes: Alarm, Task, Timeout

Constant Summary collapse

VERSION = 
"0.1.2"

Instance Method Summary collapse

Constructor Details

#initialize ⇒ RCron

Returns a new instance of RCron.



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# File 'lib/rcron/scheduler.rb', line 10

def initialize
  @tasks    = []
  @mutex    = Mutex.new
  @sleeping = false
end

Instance Method Details

#enq(name, schedule, options = {}, &block) ⇒ RCron::Task Also known as: q

Enqueues a task to be run

Parameters:

  • name (String) —

    Name of the task

  • schedule (String) —

    Cron-format schedule string

  • options (Hash) (defaults to: {}) —

    Additional options for the task. :exclusive and :timeout.

Returns:

Raises:

  • (ArgumentError) 


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# File 'lib/rcron/scheduler.rb', line 21

def enq name, schedule, options = {}, &block
  raise ArgumentError.new("Block not given") unless block_given?

  new_task = nil
  @mutex.synchronize do
    @tasks << new_task = Task.send(:new,
                    self, name, schedule,
                    options[:exclusive], options[:timeout],
                    &block)
  end
  return new_task
end

#start(logger = Logger.new($stdout)) ⇒ Object

Starts the scheduler

Parameters:

  • logger (defaults to: Logger.new($stdout)) —

    Logger instance. Default is a Logger to standard output.



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# File 'lib/rcron/scheduler.rb', line 37

def start logger = Logger.new($stdout)
  unless [:info, :warn, :error].all? { |m| logger.respond_to? m }
    raise ArgumentError.new("Invalid Logger")
  end

  @logger = logger
  @thread = Thread.current

  info "rcron started"

  now = Time.now
  while @tasks.length > 0
    # At every minute
    next_tick = Time.at( (now + 60 - now.sec).to_i )
    interval = @tasks.select(&:running?).map(&:timeout).compact.min
    begin
      @mutex.synchronize { @sleeping = true }
      #puts [ next_tick - now, interval ].compact.min
      sleep [ next_tick - now, interval ].compact.min
      @mutex.synchronize { @sleeping = false }
    rescue RCron::Alarm => e
      # puts 'woke up'
    end

    # Join completed threads
    @tasks.select(&:running?).each do |t|
      t.send :join
    end

    # Removed dequeued tasks
    @tasks.reject { |e| e.running? || e.queued? }.each do |t|
      @mutex.synchronize { @tasks.delete t }
    end

    # Start new task threads if it's time
    now = Time.now
    @tasks.select { |e| e.queued? && e.scheduled?(now) }.each do |t|
      if t.running? && t.exclusive?
        warn "[#{t.name}] already running exclusively"
        next
      end

      info "[#{t.name}] started"
      t.send :start, now
    end if now >= next_tick
  end#while
  info "rcron completed"
end

#tab ⇒ String

Crontab-like tasklist

Returns:

  • (String) 


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# File 'lib/rcron/scheduler.rb', line 88

def tab
  @tasks.map { |t| "#{t.schedule_expression} #{t.name}" }.join($/)
end