Class: Daemonizer::ProcessManager

Inherits:
Object
  • Object
show all
Defined in:
lib/daemonizer/process_manager.rb

Instance Method Summary collapse

Constructor Details

#initialize(config) ⇒ ProcessManager

Returns a new instance of ProcessManager.



3
4
5
6
7
 
# File 'lib/daemonizer/process_manager.rb', line 3

def initialize(config)
  @worker_pools = {}
  @shutdown = false
  @config = config
end

Instance Method Details

#monitor_workers ⇒ Object 



17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
 
# File 'lib/daemonizer/process_manager.rb', line 17

def monitor_workers
  setup_signals

  Daemonizer.logger.debug 'Starting workers monitoring code...'
  loop do
    Daemonizer.logger.debug "Checking workers' health..."
    @worker_pools.each do |name, pool|
      break if shutdown?
      pool.check_workers
    end

    break if shutdown?
    Daemonizer.logger.debug "Sleeping for #{@config.poll_period} seconds..." 
    sleep(@config.poll_period)
  end
ensure
  Daemonizer.logger.debug "Workers monitoring loop is finished, starting shutdown..."
  # Send out stop signals
  stop_workers(false)

  # Wait for all the workers to die
  unless wait_for_workers(10)
    Daemonizer.logger.warn "Some workers are still alive after 10 seconds of waiting. Killing them..."
    stop_workers(true)
    wait_for_workers(5)
  end
end

#setup_signals ⇒ Object 



45
46
47
48
49
 
# File 'lib/daemonizer/process_manager.rb', line 45

def setup_signals
  # Zombie reapers
  trap('CHLD') {}
  trap('EXIT') {}
end

#shutdown? ⇒ Boolean

Returns:

  • (Boolean) 


82
83
84
 
# File 'lib/daemonizer/process_manager.rb', line 82

def shutdown?
  @shutdown
end

#start_shutdown! ⇒ Object 



86
87
88
89
 
# File 'lib/daemonizer/process_manager.rb', line 86

def start_shutdown!
  Daemonizer.logger.debug "Starting shutdown (shutdown flag set)..."
  @shutdown = true
end

#start_workers(&blk) ⇒ Object

Raises:

  • (ArgumentError) 


10
11
12
13
14
15
 
# File 'lib/daemonizer/process_manager.rb', line 10

def start_workers(&blk)
  raise ArgumentError, "Need a worker block!" unless block_given?
  Daemonizer.logger.info "starting all workers"
  @worker_pools[@config.pool] = WorkerPool.new(@config.pool, self, &blk)
  @worker_pools[@config.pool].start_workers(@config.workers)
end

#stop_workers(force = false) ⇒ Object 



72
73
74
75
76
77
78
79
80
 
# File 'lib/daemonizer/process_manager.rb', line 72

def stop_workers(force = false)
  # Set shutdown flag
  Daemonizer.logger.debug "Stopping workers#{force ? ' (forced)' : ''}..."

  # Termination loop
  @worker_pools.each do |name, pool|
    pool.stop_workers(force)
  end
end

#wait_for_workers(seconds) ⇒ Object 



51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
 
# File 'lib/daemonizer/process_manager.rb', line 51

def wait_for_workers(seconds)
  seconds.times do
    Daemonizer.logger.debug "Shutting down... waiting for workers to die (we have #{seconds} seconds)..."
    running_total = 0

    @worker_pools.each do |name, pool|
      running_total += pool.wait_workers
    end

    if running_total.zero?
      Daemonizer.logger.debug "All workers are dead. Exiting..."
      return true
    end

    Daemonizer.logger.debug "#{running_total} workers are still running! Sleeping for a second..."
    sleep(1)
  end

  return false
end