Async::ContainerSourceAsyncContainerGroup

class Group

Manages a group of running processes.

Definitions

def initialize(health_check_interval: 1.0)

Initialize an empty group.

Signature

parameter health_check_interval Numeric | Nil

The (biggest) interval at which health checks are performed.

Implementation

def initialize(health_check_interval: 1.0)
	@health_check_interval = health_check_interval
	
	# The running fibers, indexed by IO:
	@running = {}
	
	# This queue allows us to wait for processes to complete, without spawning new processes as a result.
	@queue = nil
end

def inspect

Signature

returns String

A human-readable representation of the group.

Implementation

def inspect
	"#<#{self.class} running=#{@running.size}>"
end

attr :running

Signature

attribute Hash(IO, Fiber)

the running tasks, indexed by IO.

def size

Signature

returns Integer

The number of running processes.

Implementation

def size
	@running.size
end

def running?

Whether the group contains any running processes.

Signature

returns Boolean

Implementation

def running?
	@running.any?
end

def any?

Whether the group contains any running processes.

Signature

returns Boolean

Implementation

def any?
	@running.any?
end

def empty?

Whether the group is empty.

Signature

returns Boolean

Implementation

def empty?
	@running.empty?
end

def sleep(duration)

Sleep for at most the specified duration until some state change occurs.

Implementation

def sleep(duration)
	self.resume
	self.suspend
	
	self.wait_for_children(duration)
end

def wait

Begin any outstanding queued processes and wait for them indefinitely.

Implementation

def wait
	self.resume
	
	with_health_checks do |duration|
		self.wait_for_children(duration)
	end
end

def health_check!

Perform a health check on all running processes.

Implementation

def health_check!
	@running.each_value do |fiber|
		fiber.resume(:health_check!)
	end
end

def interrupt

Interrupt all running processes. This resumes the controlling fiber with an instance of Interrupt = ::Interrupt.

Implementation

def interrupt
	Console.info(self, "Sending interrupt to #{@running.size} running processes...")
	@running.each_value do |fiber|
		fiber.resume(Interrupt)
	end
end

def terminate

Terminate all running processes. This resumes the controlling fiber with an instance of class Async::Container::Terminate.

Implementation

def terminate
	Console.info(self, "Sending terminate to #{@running.size} running processes...")
	@running.each_value do |fiber|
		fiber.resume(Terminate)
	end
end

def stop(timeout = 1)

Stop all child processes using #terminate.

Signature

parameter timeout Boolean | Numeric | Nil

If specified, invoke a graceful shutdown using #interrupt first.

Implementation

def stop(timeout = 1)
	Console.debug(self, "Stopping all processes...", timeout: timeout)
	# Use a default timeout if not specified:
	timeout = 1 if timeout == true
	
	if timeout
		start_time = Async::Clock.now
		
		self.interrupt
		
		while self.any?
			duration = Async::Clock.now - start_time
			remaining = timeout - duration
			
			if remaining >= 0
				self.wait_for_children(duration)
			else
				self.wait_for_children(0)
				break
			end
		end
	end
	
	# Terminate all children:
	self.terminate if any?
	
	# Wait for all children to exit:
	self.wait
end

def wait_for(channel)

Wait for a message in the specified class Async::Container::Channel.

Implementation

def wait_for(channel)
	io = channel.in
	
	@running[io] = Fiber.current
	
	while @running.key?(io)
		# Wait for some event on the channel:
		result = Fiber.yield
		
		if result == Interrupt
			channel.interrupt!
		elsif result == Terminate
			channel.terminate!
		elsif result
			yield result
		elsif message = channel.receive
			yield message
		else
			# Wait for the channel to exit:
			return channel.wait
		end
	end
ensure
	@running.delete(io)
end

def select(duration)

Wait for a child process to exit OR a signal to be received.

Implementation

def select(duration)
	::Thread.handle_interrupt(SignalException => :immediate) do
		readable, _, _ = ::IO.select(@running.keys, nil, nil, duration)
		
		return readable
	end
end