Class: OpenC3::Throttle

Inherits:
Object show all
Defined in:
lib/openc3/utilities/throttle.rb

Constant Summary collapse

MIN_SLEEP_SECONDS = 
0.001
MAX_SLEEP_SECONDS = 
0.100

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(max_cpu_utilization) ⇒ Throttle

Returns a new instance of Throttle.

Parameters:

  • max_cpu_utilization (Float) —

    0.0-100.0



39
40
41
42
43
44
 
# File 'lib/openc3/utilities/throttle.rb', line 39

def initialize(max_cpu_utilization)
  @max_cpu_utilization = Float(max_cpu_utilization)
  raise ArgumentError "max_cpu_utilization must be between 0.0 and 100.0" if @max_cpu_utilization > 100.0 or @max_cpu_utilization < 0.0
  @max_cpu_utilization /= 100.0 # Normalize
  reset()
end

Instance Attribute Details

#reset_time ⇒ Object (readonly)

Returns the value of attribute reset_time.



35
36
37
 
# File 'lib/openc3/utilities/throttle.rb', line 35

def reset_time
  @reset_time
end

#total_sleep_time ⇒ Object (readonly)

Returns the value of attribute total_sleep_time.



36
37
38
 
# File 'lib/openc3/utilities/throttle.rb', line 36

def total_sleep_time
  @total_sleep_time
end

Instance Method Details

#reset ⇒ Object 



46
47
48
49
 
# File 'lib/openc3/utilities/throttle.rb', line 46

def reset
  @reset_time = Time.now
  @total_sleep_time = 0
end

#throttle_sleep ⇒ Object 



51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
 
# File 'lib/openc3/utilities/throttle.rb', line 51

def throttle_sleep
  return if @max_cpu_utilization >= 1.0
  total_time = Time.now - @reset_time
  if total_time > 0
    cpu_utilization = 1.0 - (@total_sleep_time / total_time)
    if cpu_utilization > @max_cpu_utilization
      # Need to throttle
      # max_cpu_utilization = sleep_time + total_sleep_time
      #                       ----------------------------
      #                       total_time
      #
      # (max_cpu_utilization * total_time) = sleep_time + total_sleep_time
      #
      # sleep_time = (max_cpu_utilization * total_time) - total_sleep_time
      #
      sleep_time = (@max_cpu_utilization * total_time) - @total_sleep_time
      if sleep_time > MIN_SLEEP_SECONDS
        sleep_time = MAX_SLEEP_SECONDS if sleep_time > MAX_SLEEP_SECONDS
        sleep(sleep_time)
        @total_sleep_time += sleep_time
      end
    end
  end
end