Class: Async::Container::Generic

Inherits:
Object
  • Object
show all
Defined in:
lib/async/container/generic.rb

Overview

A base class for implementing containers.

Direct Known Subclasses

Forked, Threaded

Constant Summary collapse

UNNAMED = 
"Unnamed"

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(**options) ⇒ Generic

Initialize the container.



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# File 'lib/async/container/generic.rb', line 46

def initialize(**options)
  @group = Group.new(**options)
  @running = true
  
  @state = {}
  
  @statistics = Statistics.new
  @keyed = {}
end

Instance Attribute Details

#group ⇒ Object (readonly)

Returns the value of attribute group.



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# File 'lib/async/container/generic.rb', line 57

def group
  @group
end

#state ⇒ Object (readonly)

Returns the value of attribute state.



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# File 'lib/async/container/generic.rb', line 65

def state
  @state
end

#statistics ⇒ Object

Statistics relating to the behavior of children instances.



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# File 'lib/async/container/generic.rb', line 81

def statistics
  @statistics
end

#The group of running children instances.(groupofrunningchildreninstances.) ⇒ Object (readonly) 



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# File 'lib/async/container/generic.rb', line 57

attr :group

Class Method Details

.run ⇒ Object

Run a new container.



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# File 'lib/async/container/generic.rb', line 37

def self.run(...)
  self.new.run(...)
end

Instance Method Details

#[](key) ⇒ Object

Look up a child process by key. A key could be a symbol, a file path, or something else which the child instance represents.



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# File 'lib/async/container/generic.rb', line 75

def [] key
  @keyed[key]&.value
end

#async(**options, &block) ⇒ Object

Deprecated.

Please use #spawn or run instead.



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# File 'lib/async/container/generic.rb', line 244

def async(**options, &block)
  # warn "#{self.class}##{__method__} is deprecated, please use `spawn` or `run` instead.", uplevel: 1
  
  require "async"
  
  spawn(**options) do |instance|
    Async(instance, &block)
  end
end

#failed? ⇒ Boolean

Whether any failures have occurred within the container.

Returns:

  • (Boolean) 


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# File 'lib/async/container/generic.rb', line 85

def failed?
  @statistics.failed?
end

#key?(key) ⇒ Boolean

Whether a child instance exists for the given key.

Returns:

  • (Boolean) 


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# File 'lib/async/container/generic.rb', line 283

def key?(key)
  if key
    @keyed.key?(key)
  end
end

#mark?(key) ⇒ Boolean

Mark the container’s keyed instance which ensures that it won’t be discarded.

Returns:

  • (Boolean) 


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# File 'lib/async/container/generic.rb', line 270

def mark?(key)
  if key
    if value = @keyed[key]
      value.mark!
      
      return true
    end
  end
  
  return false
end

#reload ⇒ Object

Reload the container’s keyed instances.



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# File 'lib/async/container/generic.rb', line 255

def reload
  @keyed.each_value(&:clear!)
  
  yield
  
  dirty = false
  
  @keyed.delete_if do |key, value|
    value.stop? && (dirty = true)
  end
  
  return dirty
end

#run(count: Container.processor_count, **options, &block) ⇒ Object

Run multiple instances of the same block in the container.



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# File 'lib/async/container/generic.rb', line 235

def run(count: Container.processor_count, **options, &block)
  count.times do
    spawn(**options, &block)
  end
  
  return self
end

#running? ⇒ Boolean

Whether the container has running children instances.

Returns:

  • (Boolean) 


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# File 'lib/async/container/generic.rb', line 90

def running?
  @group.running?
end

#size ⇒ Object 



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# File 'lib/async/container/generic.rb', line 60

def size
  @group.size
end

#sleep(duration = nil) ⇒ Object

Sleep until some state change occurs.



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# File 'lib/async/container/generic.rb', line 96

def sleep(duration = nil)
  @group.sleep(duration)
end

#spawn(name: nil, restart: false, key: nil, health_check_timeout: nil, &block) ⇒ Object

Spawn a child instance into the container.



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# File 'lib/async/container/generic.rb', line 171

def spawn(name: nil, restart: false, key: nil, health_check_timeout: nil, &block)
  name ||= UNNAMED
  
  if mark?(key)
    Console.debug(self, "Reusing existing child.", child: {key: key, name: name})
    return false
  end
  
  @statistics.spawn!
  
  fiber do
    while @running
      Console.debug(self, "Starting child...", child: {key: key, name: name, restart: restart, health_check_timeout: health_check_timeout}, statistics: @statistics)
      
      child = self.start(name, &block)
      state = insert(key, child)
      
      Console.debug(self, "Started child.", child: child, spawn: {key: key, restart: restart, health_check_timeout: health_check_timeout}, statistics: @statistics)
      
      # If a health check is specified, we will monitor the child process and terminate it if it does not update its state within the specified time.
      if health_check_timeout
        age_clock = state[:age] = Clock.start
      end
      
      status = nil
      
      begin
        status = @group.wait_for(child) do |message|
          case message
          when :health_check!
            if health_check_timeout&.<(age_clock.total)
              health_check_failed!(child, age_clock, health_check_timeout)
            end
          else
            state.update(message)
            age_clock&.reset!
          end
        end
      rescue => error
        Console.error(self, "Error during child process management!", exception: error, running: @running)
      ensure
        delete(key, child)
      end
      
      if status&.success?
        Console.debug(self, "Child exited successfully.", status: status, running: @running)
      else
        @statistics.failure!
        Console.error(self, "Child exited with error!", status: status, running: @running)
      end
      
      if restart
        @statistics.restart!
      else
        break
      end
    end
  end.resume
  
  return true
end

#status?(flag) ⇒ Boolean

Returns true if all children instances have the specified status flag set. e.g. ‘:ready`. This state is updated by the process readiness protocol mechanism. See Notify::Client for more details.

Returns:

  • (Boolean) 


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# File 'lib/async/container/generic.rb', line 109

def status?(flag)
  # This also returns true if all processes have exited/failed:
  @state.all?{|_, state| state[flag]}
end

#stop(timeout = true) ⇒ Object

Stop the children instances.



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# File 'lib/async/container/generic.rb', line 142

def stop(timeout = true)
  Console.info(self, "Stopping container...", timeout: timeout, caller: caller_locations)
  @running = false
  @group.stop(timeout)
  
  if @group.running?
    Console.warn(self, "Group is still running after stopping it!")
  else
    Console.info(self, "Group has stopped.")
  end
rescue => error
  Console.error(self, "Error while stopping container!", exception: error)
  raise
ensure
  @running = true
end

#The state of each child instance.=(stateofeachchildinstance. = (value)) ⇒ Object 



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# File 'lib/async/container/generic.rb', line 65

attr :state

#to_s ⇒ Object

A human readable representation of the container.



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# File 'lib/async/container/generic.rb', line 69

def to_s
  "#{self.class} with #{@statistics.spawns} spawns and #{@statistics.failures} failures."
end

#wait ⇒ Object

Wait until all spawned tasks are completed.



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# File 'lib/async/container/generic.rb', line 101

def wait
  @group.wait
end

#wait_until_ready ⇒ Object

Wait until all the children instances have indicated that they are ready.



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# File 'lib/async/container/generic.rb', line 116

def wait_until_ready
  while true
    Console.debug(self) do |buffer|
      buffer.puts "Waiting for ready:"
      @state.each do |child, state|
        buffer.puts "\t#{child.inspect}: #{state}"
      end
    end
    
    self.sleep
    
    if self.status?(:ready)
      Console.logger.debug(self) do |buffer|
        buffer.puts "All ready:"
        @state.each do |child, state|
          buffer.puts "\t#{child.inspect}: #{state}"
        end
      end
      
      return true
    end
  end
end