Class: Futuroscope::Future

Inherits:
Delegator
  • Object
show all
Extended by:
Forwardable
Defined in:
lib/futuroscope/future.rb

Overview

A Future is an object that gets initialized with a block and will behave exactly like the block’s result, but being able to “borrow” its result from the future. That is, will block when the result is not ready until it is, and will return it instantly if the thread’s execution already finished.

Instance Method Summary collapse

Constructor Details

#initialize(pool = ::Futuroscope.default_pool, &block) ⇒ Future

Initializes a future with a block and starts its execution.

Examples:

future = Futuroscope::Future.new { sleep(1); :edballs }
sleep(1)
puts future
=> :edballs
# This will return in 1 second and not 2 if the execution wasn't
# deferred to a thread.

pool - A pool where all the futures will be scheduled. block - A block that will be run in the background.

Returns a Future



28
29
30
31
32
33
 
# File 'lib/futuroscope/future.rb', line 28

def initialize(pool = ::Futuroscope.default_pool, &block)
  @queue = ::SizedQueue.new(1)
  @pool = pool
  @block = block
  @pool.queue self
end

Instance Method Details

#__getobj__ ⇒ Object

Semipublic: Returns the future’s value. Will wait for the future to be completed or return its value otherwise. Can be called multiple times.

Returns the Future’s block execution result.



46
47
48
49
50
51
 
# File 'lib/futuroscope/future.rb', line 46

def __getobj__
  resolved = resolved_future_value

  raise resolved[:exception] if resolved[:exception]
  resolved[:value]
end

#run_future ⇒ Object

Semipublic: Forces this future to be run.



36
37
38
39
40
 
# File 'lib/futuroscope/future.rb', line 36

def run_future
  @queue.push(value: @block.call)
rescue ::Exception => e
  @queue.push(exception: e)
end